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DOT HS 812 088 January 2015 Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR Prototype ATD Abdomen/Pelvis Components

Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

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Page 1: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

DOT HS 812 088 January 2015

Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR Prototype ATD AbdomenPelvis Components

DISCLAIMER

This publication is distributed by the US Department of Transportation National Highway Traffic Safety Administration in the interest of information exchange The opinions findings and conclusions expressed in this publication are those of the authors and not necessarily those of the Department of Transportation or the National Highway Traffic Safety Administration The United States Government assumes no liability for its contents or use thereof If trade or manufacturersrsquo names or products are mentioned it is because they are considered essential to the object of the publication and should not be construed as an endorsement The United States Government does not endorse products or manufacturers

Suggested APA Format Citation

Hagedorn A amp Stammen J (2015 January) Comparative evaluation of 6-year-old Hybrid III and DAPRR prototype ATD abdomenpelvis components (Report No DOT HS 812 088) Washington DC National Highway Traffic Safety Administration

i

TECHNICAL REPORT DOCUMENTATION PAGE

1 Report No DOT HS 812 088

2 Government Accession No 3 Recipients Catalog No

4 Title and Subtitle

Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR Prototype ATD AbdomenPelvis Components

January 2015

6 Performing Organization Code

NHTSANVS-311

7 Author(s) Alena Hagedorn Transportation Research Center Inc Jason Stammen PhD of NHTSArsquos Vehicle Research amp Test Center

8 Performing Organization Report No

9 Performing Organization Name and Address National Highway Traffic Safety Administration Vehicle Research and Test Center 10820 SR 347 PO Box B37 East Liberty OH 43319-0337

10 Work Unit No (TRAIS)

11 Contract or Grant No

12 Sponsoring Agency Name and Address National Highway Traffic Safety Administration 1200 New Jersey Avenue SE Washington DC 20590

13 Type of Report and Period Covered

Final Report 14 Sponsoring Agency Code

NHTSANVS-311 15 Supplementary Notes

16 Abstract A prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as DAPRR) has been developed for the Hybrid III 6-year-old child ATD The pelvis and abdomen are intended to better identify lap belt intrusion into the occupantrsquos abdomen in restraint evaluation tests More biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old ATD Both component level and dynamic sled tests were conducted on a Hybrid III 6-year-old with either the standard abdomen ndash pelvis structure (HYIII 6YO) or the prototype package with gel-filled abdomen and revised pelvis (DAPRR) Abdomen impact tests conducted with both dummies were repeatable and revealed that the DAPRR abdomen showed more penetration as test rate increased from 15 to 25 ms In addition the DAPRR abdomen stiffness was independent of test rate In belt pull tests the DAPRR was more consistent with the biofidelity corridor than the HYIII 6YO Sled tests indicated that the DAPRR was more sensitive to different types of restraint conditions than the HYIII 6YO and that current FMVSS No 213 injury assessment reference values (IARVs) were not significantly altered by DAPRR design changes from the standard Hybrid III An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in anterior superior iliac spine (ASIS) force versus abdomen penetration responses between belt pull component tests and sled testing Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels than the stiffer HYIII 6YO In summary the DAPRR prototype package appears to improve the sensitivity of the Hybrid III 6-year-old ATD to kinematic conditions associated with abdominal injury 17 Key Words

Abdomen ATD Hybrid III DAPRR 6-year-old 18 Distribution Statement Document is available to the public from the National Technical Information Service wwwntisgov

19 Security Classif (of this report)

Unclassified 20 Security Classif (of this

Unclassified page) 21 No of Pages

113 22 Price

Form DOT F 17007 (8-72) Reproduction of completed page authorized

EXECUTIVE SUMMARY

A prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as DAPRR) has been developed for the Hybrid III 6-year-old child ATD The pelvis and abdomen are intended to better identify lap belt intrusion into the occupantrsquos abdomen in child restraint tests More biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old ATD

Component level (pendulum impact and belt pull) and dynamic (sled) tests were conducted on a Hybrid III 6-year-old with either the standard abdomen ndash pelvis structure (HYIII 6YO) or the prototype package with gel-filled abdomen and revised pelvis (DAPRR) Overall for all test modes the DAPRR allowed for more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Pendulum impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed increasing penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure

In the belt pull tests abdomen force penetration curves were compared to a pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration increased in severity An alternative method for calculating abdomen penetration in the 6YO was developed and appears to have potential based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies these particular measurements did not appear to be significantly altered by DAPRR design changes

In summary the DAPRR package appears to improve the sensitivity of the Hybrid III 6-year-old ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis are more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD design Ongoing work includes refinement of the abdomen penetration measurement technique and better stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done to compare with the results from this report

ii

Table of Contents

1 Background 1

2 Methods 3

21 Pendulum Impacts to Abdomen 3

211 Methodology 4

2111 Calculating Abdomen Penetration 7

212 Results and Discussion 8

22 Seat Belt Pull Tests 14

221 Methodology 15

222 Calculating Belt Load Force Abdomen Penetration and Velocity 19

2221 Calculating Belt Loading Force 20

2222 Calculating Abdomen Penetration 20

2223 Calculating Abdomen Penetration Velocity 20

223 Results and Discussion 20

23 Sled Tests 22

231 Methodology 28

232 Abdomen Penetration 31

233 Results and Discussion 33

2331 40 kmh Sled Tests (1-4) 33

2332 FMVSS 213 (48 kmh) Tests (5-12) 39

3 Conclusions 52

iii

APPENDIX A Test 1 Plots (40 kmh 5-point Harness) 54

APPENDIX B Test 2 Plots (40 kmh Backless Booster) 58

APPENDIX C Test 3 Plots (40 kmh Highback Booster) 62

APPENDIX D Test 4 Plots (40 kmh No CRS) 66

APPENDIX E Test 5 Plots (48 kmh 5-point Harness) 70

APPENDIX F Test 6 Plots (48 kmh Backless Booster) 74

APPENDIX G Test 7 Plots (48 kmh Highback Booster) 78

APPENDIX H Test 8 Plots (48 kmh Backless Booster) 82

APPENDIX I Test 9 Plots (48 kmh Highback Booster) 86

APPENDIX J Test 10 Plots (48 kmh No CRS) 90

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle) 94

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) 98

APPENDIX M Abdomen Penetration Analysis 102

APPENDIX N Neck Loads and Chest Compression 103

iv

List of Tables

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies 3 Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO 3 Table 3 6YO Pendulum Test Instrumentation 4 Table 4 Summary of Abdomen Penetration From Pendulum Tests 8 Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts 9 Table 6 Seat Belt Pull Test Matrix 15 Table 7 6YO Seat Belt Pull Test Instrumentation 18 Table 8 Polarities for Seat Belt Testing and Calculations 19 Table 9 Seat Belt Pull Test Results 22 Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix 23 Table 11 6YO Sled Test Instrumentation 29 Table 12 6YO Sled Tests 40 kmh Current 213 IARVs 34 Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements 35 Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs 40 Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 5-8 42 Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 9-12 43

v

List of Figures Figure 1 Features of DAPRR abdomen and pelvis components 2 Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen 4 Figure 3 Alignment of the probe bar just above pelvis in the DAPRR 5 Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and

(bottom) test setup 5 Figure 5 Probe alignment in HYIII 6YO impacts 6 Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO 6 Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts 10 Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts 11 Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms 12 Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms 12 Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms 13 Figure 12 High belt position for DAPRR belt pull tests 14 Figure 13 Low belt position for DAPRR belt pull tests 14 Figure 14 Belt position for HYIII 6YO belt pull tests 15 Figure 15 DAPRR 6YO in seat belt pull device 16 Figure 16 HYIII 6YO in seat belt pull device 16 Figure 17 Setup for belt pull tests showing instrumentation 17 Figure 18 Stringpot configuration for pelvis displacement measurement 17 Figure 19 Belt and pelvis stringpot configurations 19 Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and

DAPRR (high and low belt placement tests) ndash all tests 95 psi 21 Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled

evaluation 23 Figure 22 Sled Test 1 five-point harness 24 Figure 23 Sled Test 2 backless CRS 24 Figure 24 Sled Test 3 high back CRS 24 Figure 25 Sled Test 4 three-point belt only 25 Figure 26 Sled Test 5 five-point harness 25 Figure 27 Sled Test 6 backless CRS 25 Figure 28 Sled Test 7 high back CRS 26 Figure 29 Sled Test 8 backless CRS 26 Figure 30 Sled Test 9 high back CRS 26 Figure 31 Sled Test 10 three-point belt only 27 Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle 27 Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle 28 Figure 34 Examples of seat belt accelerometers and ARS 30 Figure 35 Pelvis motion block installed in the DAPRR dummy 31 Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration

measurement 33 Figure 37 Abdomen penetration comparison for 40 kmh tests 34 Figure 38 Total ASIS force comparison for 40 kmh tests 36 Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1 37

vi

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2 37 Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3 38 Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4 38 Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR 41 Figure 44 Abdomen penetration comparison for 48 kmh tests 44 Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5 45 Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6 45 Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7 46 Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8 46 Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9 47 Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10 47 Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11 48 Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12 48 Figure 53 Top of abdomen ldquorolling outrdquo of pelvis 49 Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo 49 Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart 50 Figure 56 Total ASIS load comparison for 48 kmh tests 51 Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests 51

vii

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 2: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

DISCLAIMER

This publication is distributed by the US Department of Transportation National Highway Traffic Safety Administration in the interest of information exchange The opinions findings and conclusions expressed in this publication are those of the authors and not necessarily those of the Department of Transportation or the National Highway Traffic Safety Administration The United States Government assumes no liability for its contents or use thereof If trade or manufacturersrsquo names or products are mentioned it is because they are considered essential to the object of the publication and should not be construed as an endorsement The United States Government does not endorse products or manufacturers

Suggested APA Format Citation

Hagedorn A amp Stammen J (2015 January) Comparative evaluation of 6-year-old Hybrid III and DAPRR prototype ATD abdomenpelvis components (Report No DOT HS 812 088) Washington DC National Highway Traffic Safety Administration

i

TECHNICAL REPORT DOCUMENTATION PAGE

1 Report No DOT HS 812 088

2 Government Accession No 3 Recipients Catalog No

4 Title and Subtitle

Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR Prototype ATD AbdomenPelvis Components

January 2015

6 Performing Organization Code

NHTSANVS-311

7 Author(s) Alena Hagedorn Transportation Research Center Inc Jason Stammen PhD of NHTSArsquos Vehicle Research amp Test Center

8 Performing Organization Report No

9 Performing Organization Name and Address National Highway Traffic Safety Administration Vehicle Research and Test Center 10820 SR 347 PO Box B37 East Liberty OH 43319-0337

10 Work Unit No (TRAIS)

11 Contract or Grant No

12 Sponsoring Agency Name and Address National Highway Traffic Safety Administration 1200 New Jersey Avenue SE Washington DC 20590

13 Type of Report and Period Covered

Final Report 14 Sponsoring Agency Code

NHTSANVS-311 15 Supplementary Notes

16 Abstract A prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as DAPRR) has been developed for the Hybrid III 6-year-old child ATD The pelvis and abdomen are intended to better identify lap belt intrusion into the occupantrsquos abdomen in restraint evaluation tests More biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old ATD Both component level and dynamic sled tests were conducted on a Hybrid III 6-year-old with either the standard abdomen ndash pelvis structure (HYIII 6YO) or the prototype package with gel-filled abdomen and revised pelvis (DAPRR) Abdomen impact tests conducted with both dummies were repeatable and revealed that the DAPRR abdomen showed more penetration as test rate increased from 15 to 25 ms In addition the DAPRR abdomen stiffness was independent of test rate In belt pull tests the DAPRR was more consistent with the biofidelity corridor than the HYIII 6YO Sled tests indicated that the DAPRR was more sensitive to different types of restraint conditions than the HYIII 6YO and that current FMVSS No 213 injury assessment reference values (IARVs) were not significantly altered by DAPRR design changes from the standard Hybrid III An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in anterior superior iliac spine (ASIS) force versus abdomen penetration responses between belt pull component tests and sled testing Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels than the stiffer HYIII 6YO In summary the DAPRR prototype package appears to improve the sensitivity of the Hybrid III 6-year-old ATD to kinematic conditions associated with abdominal injury 17 Key Words

Abdomen ATD Hybrid III DAPRR 6-year-old 18 Distribution Statement Document is available to the public from the National Technical Information Service wwwntisgov

19 Security Classif (of this report)

Unclassified 20 Security Classif (of this

Unclassified page) 21 No of Pages

113 22 Price

Form DOT F 17007 (8-72) Reproduction of completed page authorized

EXECUTIVE SUMMARY

A prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as DAPRR) has been developed for the Hybrid III 6-year-old child ATD The pelvis and abdomen are intended to better identify lap belt intrusion into the occupantrsquos abdomen in child restraint tests More biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old ATD

Component level (pendulum impact and belt pull) and dynamic (sled) tests were conducted on a Hybrid III 6-year-old with either the standard abdomen ndash pelvis structure (HYIII 6YO) or the prototype package with gel-filled abdomen and revised pelvis (DAPRR) Overall for all test modes the DAPRR allowed for more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Pendulum impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed increasing penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure

In the belt pull tests abdomen force penetration curves were compared to a pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration increased in severity An alternative method for calculating abdomen penetration in the 6YO was developed and appears to have potential based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies these particular measurements did not appear to be significantly altered by DAPRR design changes

In summary the DAPRR package appears to improve the sensitivity of the Hybrid III 6-year-old ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis are more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD design Ongoing work includes refinement of the abdomen penetration measurement technique and better stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done to compare with the results from this report

ii

Table of Contents

1 Background 1

2 Methods 3

21 Pendulum Impacts to Abdomen 3

211 Methodology 4

2111 Calculating Abdomen Penetration 7

212 Results and Discussion 8

22 Seat Belt Pull Tests 14

221 Methodology 15

222 Calculating Belt Load Force Abdomen Penetration and Velocity 19

2221 Calculating Belt Loading Force 20

2222 Calculating Abdomen Penetration 20

2223 Calculating Abdomen Penetration Velocity 20

223 Results and Discussion 20

23 Sled Tests 22

231 Methodology 28

232 Abdomen Penetration 31

233 Results and Discussion 33

2331 40 kmh Sled Tests (1-4) 33

2332 FMVSS 213 (48 kmh) Tests (5-12) 39

3 Conclusions 52

iii

APPENDIX A Test 1 Plots (40 kmh 5-point Harness) 54

APPENDIX B Test 2 Plots (40 kmh Backless Booster) 58

APPENDIX C Test 3 Plots (40 kmh Highback Booster) 62

APPENDIX D Test 4 Plots (40 kmh No CRS) 66

APPENDIX E Test 5 Plots (48 kmh 5-point Harness) 70

APPENDIX F Test 6 Plots (48 kmh Backless Booster) 74

APPENDIX G Test 7 Plots (48 kmh Highback Booster) 78

APPENDIX H Test 8 Plots (48 kmh Backless Booster) 82

APPENDIX I Test 9 Plots (48 kmh Highback Booster) 86

APPENDIX J Test 10 Plots (48 kmh No CRS) 90

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle) 94

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) 98

APPENDIX M Abdomen Penetration Analysis 102

APPENDIX N Neck Loads and Chest Compression 103

iv

List of Tables

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies 3 Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO 3 Table 3 6YO Pendulum Test Instrumentation 4 Table 4 Summary of Abdomen Penetration From Pendulum Tests 8 Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts 9 Table 6 Seat Belt Pull Test Matrix 15 Table 7 6YO Seat Belt Pull Test Instrumentation 18 Table 8 Polarities for Seat Belt Testing and Calculations 19 Table 9 Seat Belt Pull Test Results 22 Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix 23 Table 11 6YO Sled Test Instrumentation 29 Table 12 6YO Sled Tests 40 kmh Current 213 IARVs 34 Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements 35 Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs 40 Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 5-8 42 Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 9-12 43

v

List of Figures Figure 1 Features of DAPRR abdomen and pelvis components 2 Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen 4 Figure 3 Alignment of the probe bar just above pelvis in the DAPRR 5 Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and

(bottom) test setup 5 Figure 5 Probe alignment in HYIII 6YO impacts 6 Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO 6 Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts 10 Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts 11 Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms 12 Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms 12 Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms 13 Figure 12 High belt position for DAPRR belt pull tests 14 Figure 13 Low belt position for DAPRR belt pull tests 14 Figure 14 Belt position for HYIII 6YO belt pull tests 15 Figure 15 DAPRR 6YO in seat belt pull device 16 Figure 16 HYIII 6YO in seat belt pull device 16 Figure 17 Setup for belt pull tests showing instrumentation 17 Figure 18 Stringpot configuration for pelvis displacement measurement 17 Figure 19 Belt and pelvis stringpot configurations 19 Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and

DAPRR (high and low belt placement tests) ndash all tests 95 psi 21 Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled

evaluation 23 Figure 22 Sled Test 1 five-point harness 24 Figure 23 Sled Test 2 backless CRS 24 Figure 24 Sled Test 3 high back CRS 24 Figure 25 Sled Test 4 three-point belt only 25 Figure 26 Sled Test 5 five-point harness 25 Figure 27 Sled Test 6 backless CRS 25 Figure 28 Sled Test 7 high back CRS 26 Figure 29 Sled Test 8 backless CRS 26 Figure 30 Sled Test 9 high back CRS 26 Figure 31 Sled Test 10 three-point belt only 27 Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle 27 Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle 28 Figure 34 Examples of seat belt accelerometers and ARS 30 Figure 35 Pelvis motion block installed in the DAPRR dummy 31 Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration

measurement 33 Figure 37 Abdomen penetration comparison for 40 kmh tests 34 Figure 38 Total ASIS force comparison for 40 kmh tests 36 Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1 37

vi

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2 37 Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3 38 Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4 38 Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR 41 Figure 44 Abdomen penetration comparison for 48 kmh tests 44 Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5 45 Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6 45 Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7 46 Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8 46 Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9 47 Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10 47 Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11 48 Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12 48 Figure 53 Top of abdomen ldquorolling outrdquo of pelvis 49 Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo 49 Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart 50 Figure 56 Total ASIS load comparison for 48 kmh tests 51 Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests 51

vii

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 3: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

i

TECHNICAL REPORT DOCUMENTATION PAGE

1 Report No DOT HS 812 088

2 Government Accession No 3 Recipients Catalog No

4 Title and Subtitle

Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR Prototype ATD AbdomenPelvis Components

January 2015

6 Performing Organization Code

NHTSANVS-311

7 Author(s) Alena Hagedorn Transportation Research Center Inc Jason Stammen PhD of NHTSArsquos Vehicle Research amp Test Center

8 Performing Organization Report No

9 Performing Organization Name and Address National Highway Traffic Safety Administration Vehicle Research and Test Center 10820 SR 347 PO Box B37 East Liberty OH 43319-0337

10 Work Unit No (TRAIS)

11 Contract or Grant No

12 Sponsoring Agency Name and Address National Highway Traffic Safety Administration 1200 New Jersey Avenue SE Washington DC 20590

13 Type of Report and Period Covered

Final Report 14 Sponsoring Agency Code

NHTSANVS-311 15 Supplementary Notes

16 Abstract A prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as DAPRR) has been developed for the Hybrid III 6-year-old child ATD The pelvis and abdomen are intended to better identify lap belt intrusion into the occupantrsquos abdomen in restraint evaluation tests More biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old ATD Both component level and dynamic sled tests were conducted on a Hybrid III 6-year-old with either the standard abdomen ndash pelvis structure (HYIII 6YO) or the prototype package with gel-filled abdomen and revised pelvis (DAPRR) Abdomen impact tests conducted with both dummies were repeatable and revealed that the DAPRR abdomen showed more penetration as test rate increased from 15 to 25 ms In addition the DAPRR abdomen stiffness was independent of test rate In belt pull tests the DAPRR was more consistent with the biofidelity corridor than the HYIII 6YO Sled tests indicated that the DAPRR was more sensitive to different types of restraint conditions than the HYIII 6YO and that current FMVSS No 213 injury assessment reference values (IARVs) were not significantly altered by DAPRR design changes from the standard Hybrid III An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in anterior superior iliac spine (ASIS) force versus abdomen penetration responses between belt pull component tests and sled testing Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels than the stiffer HYIII 6YO In summary the DAPRR prototype package appears to improve the sensitivity of the Hybrid III 6-year-old ATD to kinematic conditions associated with abdominal injury 17 Key Words

Abdomen ATD Hybrid III DAPRR 6-year-old 18 Distribution Statement Document is available to the public from the National Technical Information Service wwwntisgov

19 Security Classif (of this report)

Unclassified 20 Security Classif (of this

Unclassified page) 21 No of Pages

113 22 Price

Form DOT F 17007 (8-72) Reproduction of completed page authorized

EXECUTIVE SUMMARY

A prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as DAPRR) has been developed for the Hybrid III 6-year-old child ATD The pelvis and abdomen are intended to better identify lap belt intrusion into the occupantrsquos abdomen in child restraint tests More biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old ATD

Component level (pendulum impact and belt pull) and dynamic (sled) tests were conducted on a Hybrid III 6-year-old with either the standard abdomen ndash pelvis structure (HYIII 6YO) or the prototype package with gel-filled abdomen and revised pelvis (DAPRR) Overall for all test modes the DAPRR allowed for more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Pendulum impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed increasing penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure

In the belt pull tests abdomen force penetration curves were compared to a pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration increased in severity An alternative method for calculating abdomen penetration in the 6YO was developed and appears to have potential based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies these particular measurements did not appear to be significantly altered by DAPRR design changes

In summary the DAPRR package appears to improve the sensitivity of the Hybrid III 6-year-old ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis are more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD design Ongoing work includes refinement of the abdomen penetration measurement technique and better stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done to compare with the results from this report

ii

Table of Contents

1 Background 1

2 Methods 3

21 Pendulum Impacts to Abdomen 3

211 Methodology 4

2111 Calculating Abdomen Penetration 7

212 Results and Discussion 8

22 Seat Belt Pull Tests 14

221 Methodology 15

222 Calculating Belt Load Force Abdomen Penetration and Velocity 19

2221 Calculating Belt Loading Force 20

2222 Calculating Abdomen Penetration 20

2223 Calculating Abdomen Penetration Velocity 20

223 Results and Discussion 20

23 Sled Tests 22

231 Methodology 28

232 Abdomen Penetration 31

233 Results and Discussion 33

2331 40 kmh Sled Tests (1-4) 33

2332 FMVSS 213 (48 kmh) Tests (5-12) 39

3 Conclusions 52

iii

APPENDIX A Test 1 Plots (40 kmh 5-point Harness) 54

APPENDIX B Test 2 Plots (40 kmh Backless Booster) 58

APPENDIX C Test 3 Plots (40 kmh Highback Booster) 62

APPENDIX D Test 4 Plots (40 kmh No CRS) 66

APPENDIX E Test 5 Plots (48 kmh 5-point Harness) 70

APPENDIX F Test 6 Plots (48 kmh Backless Booster) 74

APPENDIX G Test 7 Plots (48 kmh Highback Booster) 78

APPENDIX H Test 8 Plots (48 kmh Backless Booster) 82

APPENDIX I Test 9 Plots (48 kmh Highback Booster) 86

APPENDIX J Test 10 Plots (48 kmh No CRS) 90

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle) 94

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) 98

APPENDIX M Abdomen Penetration Analysis 102

APPENDIX N Neck Loads and Chest Compression 103

iv

List of Tables

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies 3 Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO 3 Table 3 6YO Pendulum Test Instrumentation 4 Table 4 Summary of Abdomen Penetration From Pendulum Tests 8 Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts 9 Table 6 Seat Belt Pull Test Matrix 15 Table 7 6YO Seat Belt Pull Test Instrumentation 18 Table 8 Polarities for Seat Belt Testing and Calculations 19 Table 9 Seat Belt Pull Test Results 22 Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix 23 Table 11 6YO Sled Test Instrumentation 29 Table 12 6YO Sled Tests 40 kmh Current 213 IARVs 34 Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements 35 Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs 40 Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 5-8 42 Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 9-12 43

v

List of Figures Figure 1 Features of DAPRR abdomen and pelvis components 2 Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen 4 Figure 3 Alignment of the probe bar just above pelvis in the DAPRR 5 Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and

(bottom) test setup 5 Figure 5 Probe alignment in HYIII 6YO impacts 6 Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO 6 Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts 10 Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts 11 Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms 12 Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms 12 Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms 13 Figure 12 High belt position for DAPRR belt pull tests 14 Figure 13 Low belt position for DAPRR belt pull tests 14 Figure 14 Belt position for HYIII 6YO belt pull tests 15 Figure 15 DAPRR 6YO in seat belt pull device 16 Figure 16 HYIII 6YO in seat belt pull device 16 Figure 17 Setup for belt pull tests showing instrumentation 17 Figure 18 Stringpot configuration for pelvis displacement measurement 17 Figure 19 Belt and pelvis stringpot configurations 19 Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and

DAPRR (high and low belt placement tests) ndash all tests 95 psi 21 Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled

evaluation 23 Figure 22 Sled Test 1 five-point harness 24 Figure 23 Sled Test 2 backless CRS 24 Figure 24 Sled Test 3 high back CRS 24 Figure 25 Sled Test 4 three-point belt only 25 Figure 26 Sled Test 5 five-point harness 25 Figure 27 Sled Test 6 backless CRS 25 Figure 28 Sled Test 7 high back CRS 26 Figure 29 Sled Test 8 backless CRS 26 Figure 30 Sled Test 9 high back CRS 26 Figure 31 Sled Test 10 three-point belt only 27 Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle 27 Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle 28 Figure 34 Examples of seat belt accelerometers and ARS 30 Figure 35 Pelvis motion block installed in the DAPRR dummy 31 Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration

measurement 33 Figure 37 Abdomen penetration comparison for 40 kmh tests 34 Figure 38 Total ASIS force comparison for 40 kmh tests 36 Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1 37

vi

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2 37 Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3 38 Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4 38 Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR 41 Figure 44 Abdomen penetration comparison for 48 kmh tests 44 Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5 45 Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6 45 Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7 46 Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8 46 Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9 47 Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10 47 Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11 48 Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12 48 Figure 53 Top of abdomen ldquorolling outrdquo of pelvis 49 Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo 49 Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart 50 Figure 56 Total ASIS load comparison for 48 kmh tests 51 Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests 51

vii

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 4: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

EXECUTIVE SUMMARY

A prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as DAPRR) has been developed for the Hybrid III 6-year-old child ATD The pelvis and abdomen are intended to better identify lap belt intrusion into the occupantrsquos abdomen in child restraint tests More biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old ATD

Component level (pendulum impact and belt pull) and dynamic (sled) tests were conducted on a Hybrid III 6-year-old with either the standard abdomen ndash pelvis structure (HYIII 6YO) or the prototype package with gel-filled abdomen and revised pelvis (DAPRR) Overall for all test modes the DAPRR allowed for more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Pendulum impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed increasing penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure

In the belt pull tests abdomen force penetration curves were compared to a pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration increased in severity An alternative method for calculating abdomen penetration in the 6YO was developed and appears to have potential based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies these particular measurements did not appear to be significantly altered by DAPRR design changes

In summary the DAPRR package appears to improve the sensitivity of the Hybrid III 6-year-old ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis are more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD design Ongoing work includes refinement of the abdomen penetration measurement technique and better stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done to compare with the results from this report

ii

Table of Contents

1 Background 1

2 Methods 3

21 Pendulum Impacts to Abdomen 3

211 Methodology 4

2111 Calculating Abdomen Penetration 7

212 Results and Discussion 8

22 Seat Belt Pull Tests 14

221 Methodology 15

222 Calculating Belt Load Force Abdomen Penetration and Velocity 19

2221 Calculating Belt Loading Force 20

2222 Calculating Abdomen Penetration 20

2223 Calculating Abdomen Penetration Velocity 20

223 Results and Discussion 20

23 Sled Tests 22

231 Methodology 28

232 Abdomen Penetration 31

233 Results and Discussion 33

2331 40 kmh Sled Tests (1-4) 33

2332 FMVSS 213 (48 kmh) Tests (5-12) 39

3 Conclusions 52

iii

APPENDIX A Test 1 Plots (40 kmh 5-point Harness) 54

APPENDIX B Test 2 Plots (40 kmh Backless Booster) 58

APPENDIX C Test 3 Plots (40 kmh Highback Booster) 62

APPENDIX D Test 4 Plots (40 kmh No CRS) 66

APPENDIX E Test 5 Plots (48 kmh 5-point Harness) 70

APPENDIX F Test 6 Plots (48 kmh Backless Booster) 74

APPENDIX G Test 7 Plots (48 kmh Highback Booster) 78

APPENDIX H Test 8 Plots (48 kmh Backless Booster) 82

APPENDIX I Test 9 Plots (48 kmh Highback Booster) 86

APPENDIX J Test 10 Plots (48 kmh No CRS) 90

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle) 94

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) 98

APPENDIX M Abdomen Penetration Analysis 102

APPENDIX N Neck Loads and Chest Compression 103

iv

List of Tables

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies 3 Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO 3 Table 3 6YO Pendulum Test Instrumentation 4 Table 4 Summary of Abdomen Penetration From Pendulum Tests 8 Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts 9 Table 6 Seat Belt Pull Test Matrix 15 Table 7 6YO Seat Belt Pull Test Instrumentation 18 Table 8 Polarities for Seat Belt Testing and Calculations 19 Table 9 Seat Belt Pull Test Results 22 Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix 23 Table 11 6YO Sled Test Instrumentation 29 Table 12 6YO Sled Tests 40 kmh Current 213 IARVs 34 Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements 35 Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs 40 Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 5-8 42 Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 9-12 43

v

List of Figures Figure 1 Features of DAPRR abdomen and pelvis components 2 Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen 4 Figure 3 Alignment of the probe bar just above pelvis in the DAPRR 5 Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and

(bottom) test setup 5 Figure 5 Probe alignment in HYIII 6YO impacts 6 Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO 6 Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts 10 Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts 11 Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms 12 Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms 12 Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms 13 Figure 12 High belt position for DAPRR belt pull tests 14 Figure 13 Low belt position for DAPRR belt pull tests 14 Figure 14 Belt position for HYIII 6YO belt pull tests 15 Figure 15 DAPRR 6YO in seat belt pull device 16 Figure 16 HYIII 6YO in seat belt pull device 16 Figure 17 Setup for belt pull tests showing instrumentation 17 Figure 18 Stringpot configuration for pelvis displacement measurement 17 Figure 19 Belt and pelvis stringpot configurations 19 Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and

DAPRR (high and low belt placement tests) ndash all tests 95 psi 21 Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled

evaluation 23 Figure 22 Sled Test 1 five-point harness 24 Figure 23 Sled Test 2 backless CRS 24 Figure 24 Sled Test 3 high back CRS 24 Figure 25 Sled Test 4 three-point belt only 25 Figure 26 Sled Test 5 five-point harness 25 Figure 27 Sled Test 6 backless CRS 25 Figure 28 Sled Test 7 high back CRS 26 Figure 29 Sled Test 8 backless CRS 26 Figure 30 Sled Test 9 high back CRS 26 Figure 31 Sled Test 10 three-point belt only 27 Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle 27 Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle 28 Figure 34 Examples of seat belt accelerometers and ARS 30 Figure 35 Pelvis motion block installed in the DAPRR dummy 31 Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration

measurement 33 Figure 37 Abdomen penetration comparison for 40 kmh tests 34 Figure 38 Total ASIS force comparison for 40 kmh tests 36 Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1 37

vi

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2 37 Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3 38 Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4 38 Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR 41 Figure 44 Abdomen penetration comparison for 48 kmh tests 44 Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5 45 Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6 45 Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7 46 Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8 46 Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9 47 Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10 47 Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11 48 Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12 48 Figure 53 Top of abdomen ldquorolling outrdquo of pelvis 49 Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo 49 Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart 50 Figure 56 Total ASIS load comparison for 48 kmh tests 51 Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests 51

vii

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 5: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Table of Contents

1 Background 1

2 Methods 3

21 Pendulum Impacts to Abdomen 3

211 Methodology 4

2111 Calculating Abdomen Penetration 7

212 Results and Discussion 8

22 Seat Belt Pull Tests 14

221 Methodology 15

222 Calculating Belt Load Force Abdomen Penetration and Velocity 19

2221 Calculating Belt Loading Force 20

2222 Calculating Abdomen Penetration 20

2223 Calculating Abdomen Penetration Velocity 20

223 Results and Discussion 20

23 Sled Tests 22

231 Methodology 28

232 Abdomen Penetration 31

233 Results and Discussion 33

2331 40 kmh Sled Tests (1-4) 33

2332 FMVSS 213 (48 kmh) Tests (5-12) 39

3 Conclusions 52

iii

APPENDIX A Test 1 Plots (40 kmh 5-point Harness) 54

APPENDIX B Test 2 Plots (40 kmh Backless Booster) 58

APPENDIX C Test 3 Plots (40 kmh Highback Booster) 62

APPENDIX D Test 4 Plots (40 kmh No CRS) 66

APPENDIX E Test 5 Plots (48 kmh 5-point Harness) 70

APPENDIX F Test 6 Plots (48 kmh Backless Booster) 74

APPENDIX G Test 7 Plots (48 kmh Highback Booster) 78

APPENDIX H Test 8 Plots (48 kmh Backless Booster) 82

APPENDIX I Test 9 Plots (48 kmh Highback Booster) 86

APPENDIX J Test 10 Plots (48 kmh No CRS) 90

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle) 94

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) 98

APPENDIX M Abdomen Penetration Analysis 102

APPENDIX N Neck Loads and Chest Compression 103

iv

List of Tables

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies 3 Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO 3 Table 3 6YO Pendulum Test Instrumentation 4 Table 4 Summary of Abdomen Penetration From Pendulum Tests 8 Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts 9 Table 6 Seat Belt Pull Test Matrix 15 Table 7 6YO Seat Belt Pull Test Instrumentation 18 Table 8 Polarities for Seat Belt Testing and Calculations 19 Table 9 Seat Belt Pull Test Results 22 Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix 23 Table 11 6YO Sled Test Instrumentation 29 Table 12 6YO Sled Tests 40 kmh Current 213 IARVs 34 Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements 35 Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs 40 Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 5-8 42 Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 9-12 43

v

List of Figures Figure 1 Features of DAPRR abdomen and pelvis components 2 Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen 4 Figure 3 Alignment of the probe bar just above pelvis in the DAPRR 5 Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and

(bottom) test setup 5 Figure 5 Probe alignment in HYIII 6YO impacts 6 Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO 6 Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts 10 Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts 11 Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms 12 Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms 12 Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms 13 Figure 12 High belt position for DAPRR belt pull tests 14 Figure 13 Low belt position for DAPRR belt pull tests 14 Figure 14 Belt position for HYIII 6YO belt pull tests 15 Figure 15 DAPRR 6YO in seat belt pull device 16 Figure 16 HYIII 6YO in seat belt pull device 16 Figure 17 Setup for belt pull tests showing instrumentation 17 Figure 18 Stringpot configuration for pelvis displacement measurement 17 Figure 19 Belt and pelvis stringpot configurations 19 Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and

DAPRR (high and low belt placement tests) ndash all tests 95 psi 21 Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled

evaluation 23 Figure 22 Sled Test 1 five-point harness 24 Figure 23 Sled Test 2 backless CRS 24 Figure 24 Sled Test 3 high back CRS 24 Figure 25 Sled Test 4 three-point belt only 25 Figure 26 Sled Test 5 five-point harness 25 Figure 27 Sled Test 6 backless CRS 25 Figure 28 Sled Test 7 high back CRS 26 Figure 29 Sled Test 8 backless CRS 26 Figure 30 Sled Test 9 high back CRS 26 Figure 31 Sled Test 10 three-point belt only 27 Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle 27 Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle 28 Figure 34 Examples of seat belt accelerometers and ARS 30 Figure 35 Pelvis motion block installed in the DAPRR dummy 31 Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration

measurement 33 Figure 37 Abdomen penetration comparison for 40 kmh tests 34 Figure 38 Total ASIS force comparison for 40 kmh tests 36 Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1 37

vi

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2 37 Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3 38 Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4 38 Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR 41 Figure 44 Abdomen penetration comparison for 48 kmh tests 44 Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5 45 Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6 45 Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7 46 Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8 46 Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9 47 Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10 47 Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11 48 Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12 48 Figure 53 Top of abdomen ldquorolling outrdquo of pelvis 49 Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo 49 Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart 50 Figure 56 Total ASIS load comparison for 48 kmh tests 51 Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests 51

vii

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 6: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX A Test 1 Plots (40 kmh 5-point Harness) 54

APPENDIX B Test 2 Plots (40 kmh Backless Booster) 58

APPENDIX C Test 3 Plots (40 kmh Highback Booster) 62

APPENDIX D Test 4 Plots (40 kmh No CRS) 66

APPENDIX E Test 5 Plots (48 kmh 5-point Harness) 70

APPENDIX F Test 6 Plots (48 kmh Backless Booster) 74

APPENDIX G Test 7 Plots (48 kmh Highback Booster) 78

APPENDIX H Test 8 Plots (48 kmh Backless Booster) 82

APPENDIX I Test 9 Plots (48 kmh Highback Booster) 86

APPENDIX J Test 10 Plots (48 kmh No CRS) 90

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle) 94

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) 98

APPENDIX M Abdomen Penetration Analysis 102

APPENDIX N Neck Loads and Chest Compression 103

iv

List of Tables

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies 3 Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO 3 Table 3 6YO Pendulum Test Instrumentation 4 Table 4 Summary of Abdomen Penetration From Pendulum Tests 8 Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts 9 Table 6 Seat Belt Pull Test Matrix 15 Table 7 6YO Seat Belt Pull Test Instrumentation 18 Table 8 Polarities for Seat Belt Testing and Calculations 19 Table 9 Seat Belt Pull Test Results 22 Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix 23 Table 11 6YO Sled Test Instrumentation 29 Table 12 6YO Sled Tests 40 kmh Current 213 IARVs 34 Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements 35 Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs 40 Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 5-8 42 Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 9-12 43

v

List of Figures Figure 1 Features of DAPRR abdomen and pelvis components 2 Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen 4 Figure 3 Alignment of the probe bar just above pelvis in the DAPRR 5 Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and

(bottom) test setup 5 Figure 5 Probe alignment in HYIII 6YO impacts 6 Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO 6 Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts 10 Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts 11 Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms 12 Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms 12 Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms 13 Figure 12 High belt position for DAPRR belt pull tests 14 Figure 13 Low belt position for DAPRR belt pull tests 14 Figure 14 Belt position for HYIII 6YO belt pull tests 15 Figure 15 DAPRR 6YO in seat belt pull device 16 Figure 16 HYIII 6YO in seat belt pull device 16 Figure 17 Setup for belt pull tests showing instrumentation 17 Figure 18 Stringpot configuration for pelvis displacement measurement 17 Figure 19 Belt and pelvis stringpot configurations 19 Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and

DAPRR (high and low belt placement tests) ndash all tests 95 psi 21 Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled

evaluation 23 Figure 22 Sled Test 1 five-point harness 24 Figure 23 Sled Test 2 backless CRS 24 Figure 24 Sled Test 3 high back CRS 24 Figure 25 Sled Test 4 three-point belt only 25 Figure 26 Sled Test 5 five-point harness 25 Figure 27 Sled Test 6 backless CRS 25 Figure 28 Sled Test 7 high back CRS 26 Figure 29 Sled Test 8 backless CRS 26 Figure 30 Sled Test 9 high back CRS 26 Figure 31 Sled Test 10 three-point belt only 27 Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle 27 Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle 28 Figure 34 Examples of seat belt accelerometers and ARS 30 Figure 35 Pelvis motion block installed in the DAPRR dummy 31 Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration

measurement 33 Figure 37 Abdomen penetration comparison for 40 kmh tests 34 Figure 38 Total ASIS force comparison for 40 kmh tests 36 Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1 37

vi

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2 37 Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3 38 Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4 38 Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR 41 Figure 44 Abdomen penetration comparison for 48 kmh tests 44 Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5 45 Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6 45 Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7 46 Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8 46 Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9 47 Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10 47 Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11 48 Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12 48 Figure 53 Top of abdomen ldquorolling outrdquo of pelvis 49 Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo 49 Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart 50 Figure 56 Total ASIS load comparison for 48 kmh tests 51 Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests 51

vii

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 7: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

List of Tables

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies 3 Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO 3 Table 3 6YO Pendulum Test Instrumentation 4 Table 4 Summary of Abdomen Penetration From Pendulum Tests 8 Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts 9 Table 6 Seat Belt Pull Test Matrix 15 Table 7 6YO Seat Belt Pull Test Instrumentation 18 Table 8 Polarities for Seat Belt Testing and Calculations 19 Table 9 Seat Belt Pull Test Results 22 Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix 23 Table 11 6YO Sled Test Instrumentation 29 Table 12 6YO Sled Tests 40 kmh Current 213 IARVs 34 Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements 35 Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs 40 Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 5-8 42 Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements

Tests 9-12 43

v

List of Figures Figure 1 Features of DAPRR abdomen and pelvis components 2 Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen 4 Figure 3 Alignment of the probe bar just above pelvis in the DAPRR 5 Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and

(bottom) test setup 5 Figure 5 Probe alignment in HYIII 6YO impacts 6 Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO 6 Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts 10 Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts 11 Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms 12 Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms 12 Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms 13 Figure 12 High belt position for DAPRR belt pull tests 14 Figure 13 Low belt position for DAPRR belt pull tests 14 Figure 14 Belt position for HYIII 6YO belt pull tests 15 Figure 15 DAPRR 6YO in seat belt pull device 16 Figure 16 HYIII 6YO in seat belt pull device 16 Figure 17 Setup for belt pull tests showing instrumentation 17 Figure 18 Stringpot configuration for pelvis displacement measurement 17 Figure 19 Belt and pelvis stringpot configurations 19 Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and

DAPRR (high and low belt placement tests) ndash all tests 95 psi 21 Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled

evaluation 23 Figure 22 Sled Test 1 five-point harness 24 Figure 23 Sled Test 2 backless CRS 24 Figure 24 Sled Test 3 high back CRS 24 Figure 25 Sled Test 4 three-point belt only 25 Figure 26 Sled Test 5 five-point harness 25 Figure 27 Sled Test 6 backless CRS 25 Figure 28 Sled Test 7 high back CRS 26 Figure 29 Sled Test 8 backless CRS 26 Figure 30 Sled Test 9 high back CRS 26 Figure 31 Sled Test 10 three-point belt only 27 Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle 27 Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle 28 Figure 34 Examples of seat belt accelerometers and ARS 30 Figure 35 Pelvis motion block installed in the DAPRR dummy 31 Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration

measurement 33 Figure 37 Abdomen penetration comparison for 40 kmh tests 34 Figure 38 Total ASIS force comparison for 40 kmh tests 36 Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1 37

vi

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2 37 Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3 38 Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4 38 Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR 41 Figure 44 Abdomen penetration comparison for 48 kmh tests 44 Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5 45 Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6 45 Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7 46 Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8 46 Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9 47 Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10 47 Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11 48 Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12 48 Figure 53 Top of abdomen ldquorolling outrdquo of pelvis 49 Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo 49 Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart 50 Figure 56 Total ASIS load comparison for 48 kmh tests 51 Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests 51

vii

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 8: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

List of Figures Figure 1 Features of DAPRR abdomen and pelvis components 2 Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen 4 Figure 3 Alignment of the probe bar just above pelvis in the DAPRR 5 Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and

(bottom) test setup 5 Figure 5 Probe alignment in HYIII 6YO impacts 6 Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO 6 Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts 10 Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts 11 Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms 12 Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms 12 Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms 13 Figure 12 High belt position for DAPRR belt pull tests 14 Figure 13 Low belt position for DAPRR belt pull tests 14 Figure 14 Belt position for HYIII 6YO belt pull tests 15 Figure 15 DAPRR 6YO in seat belt pull device 16 Figure 16 HYIII 6YO in seat belt pull device 16 Figure 17 Setup for belt pull tests showing instrumentation 17 Figure 18 Stringpot configuration for pelvis displacement measurement 17 Figure 19 Belt and pelvis stringpot configurations 19 Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and

DAPRR (high and low belt placement tests) ndash all tests 95 psi 21 Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled

evaluation 23 Figure 22 Sled Test 1 five-point harness 24 Figure 23 Sled Test 2 backless CRS 24 Figure 24 Sled Test 3 high back CRS 24 Figure 25 Sled Test 4 three-point belt only 25 Figure 26 Sled Test 5 five-point harness 25 Figure 27 Sled Test 6 backless CRS 25 Figure 28 Sled Test 7 high back CRS 26 Figure 29 Sled Test 8 backless CRS 26 Figure 30 Sled Test 9 high back CRS 26 Figure 31 Sled Test 10 three-point belt only 27 Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle 27 Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle 28 Figure 34 Examples of seat belt accelerometers and ARS 30 Figure 35 Pelvis motion block installed in the DAPRR dummy 31 Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration

measurement 33 Figure 37 Abdomen penetration comparison for 40 kmh tests 34 Figure 38 Total ASIS force comparison for 40 kmh tests 36 Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1 37

vi

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2 37 Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3 38 Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4 38 Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR 41 Figure 44 Abdomen penetration comparison for 48 kmh tests 44 Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5 45 Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6 45 Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7 46 Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8 46 Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9 47 Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10 47 Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11 48 Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12 48 Figure 53 Top of abdomen ldquorolling outrdquo of pelvis 49 Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo 49 Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart 50 Figure 56 Total ASIS load comparison for 48 kmh tests 51 Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests 51

vii

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 9: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2 37 Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3 38 Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4 38 Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the

DAPRR 41 Figure 44 Abdomen penetration comparison for 48 kmh tests 44 Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5 45 Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6 45 Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7 46 Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8 46 Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9 47 Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10 47 Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11 48 Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12 48 Figure 53 Top of abdomen ldquorolling outrdquo of pelvis 49 Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo 49 Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart 50 Figure 56 Total ASIS load comparison for 48 kmh tests 51 Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and 3-point

belt sled tests 51

vii

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 10: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

1 Background

The abdomen is the second most commonly injured body region after the headface in young children using vehicle seat belts and can be associated with significant health care costs1 In a case series of 98 children with ldquoseat belt syndromerdquo injuries the mean age was 73 plusmn 25 years and 72 percent were from 5 to 9 years old2 An analysis of over 200000 children in crashes identified age as a primary factor for elevated abdominal injury risk3 Children 4 yo 8 years old were at the highest risk of abdominal injury they were 245 times and 26 times more likely to sustain an AIS2+ abdominal injury than those from birth to 3 years old and those 9 to 15 years old respectively The developmental and geometric characteristics of the 4- to 8-year-old child pelvis increase the likelihood of the vehicle belt intruding into the abdomen and causing these injuries Thus this age group is targeted as the primary age range to benefit from belt-positioning booster seat use

In addition to injury trends differences have been identified between human and child ATD pelvis geometries It has been observed that the anterior superior iliac spine (ASIS) landmark on the front of the Hybrid III 6-year-old anthropomorphic test dummy (ATD) hereafter referred to as the HYIII 6YO is higher relative to the thigh-abdomen junction than on similar sized children4 5 Given the importance of lap belt placement with respect to the pelvis it is important that the ATD pelvis has a biofidelic anthropometry

Currently there is no current pediatric ATD that can accurately track the abdominal response to belt loading and thus the risk of injury The injury trends and pelvis geometry discrepancies noted above both point to the HYIII 6YO as the prime candidate for an improved abdomenpelvis design

In the early 2000s a collaborative research effort was undertaken with the goal of developing a new ATD abdomen and pelvis design1 This effort included an epidemiological analysis of abdomen injuries to identify risk factors3 an anthropometry study to provide geometric specifications for a modified pelvis6 an experimental study to derive a pediatric abdomen

1 Arbogast K B Mong D A Marigowda S Kent R Stacey S Mattice J hellip amp Rouhana S R (2005) Evaluating pediatric abdominal injuries (Paper No 05-0046-O) In Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles June 6-9 2005 Washington DC Available at wwwshynrdnhtsadotgovpdfesvesv1905-0046-Opdf2 Gotschall C S Better A I Bulas D Eichelberger M R Bents F amp Warner M (1998) Injuries to children restrained in 2- and 3-point belts Annu Proc Assoc Adv Automot Med 42 29ndash43 3 Arbogast K B Chen I Nance M L Durbin D R amp Winston F K (2004) Predictors of pediatric abdominal injury risk Stapp Car Crash Journal48 479-494 4 Chamouard F Tarriere C amp Baudrit P (1996) Protection of children on board vehicles influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster (Paper Number 96-S7-O-03) In Proceedings of the 15th International Technical Conference on the Enhanced Safety of Vehicles May 13-16 1996 Melbourne Australia pp 1063-1075 5 Reed M P Ebert S M Sherwood CP Klinich K D amp Manary M A (2009 May) Evaluation of the static belt fit provided by belt-positioning booster seats AccidAnal Prev41(3)598ndash607 6 Reed M P Sochor M M Rupp J D Klinich K D amp Manary M A (2009) Anthropometric specification of child crash dummy pelves through statistical analysis of skeletal geometry J Biomech 42 1143-1145

1

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 11: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

response target7 and abdomen hardware capable of measuring abdominal displacement8 In 2008 and 2009 NHTSA began to actively participate in the SAE Dummy Abdomen Round Robin (DAPRR) working group by assisting in the design of a pelvis reflecting child anthropometry Subsequently NHTSA contracted Denton ATD to build five prototypes reflecting the finalized pelvis design The DAPRR working group then collaborated to integrate the Ford abdomen and pelvis prototype into the HYIII 6YO ATD as a retrofit package Once the prototype package was completed the DAPRR then moved into the evaluation stage with automakers child restraint manufacturers and other entities joining the working group to participate in round robin testing The various components of the retrofit package are currently owned by different entities with an agreed-upon understanding that the full design characteristics of the retrofit package will be made available to the public after the working group has completed its development and evaluation

A comparison between the prototype retrofit package consisting of an anthropometric pelvis and a gel-filled abdomen (together known as the DAPRR9 retrofit package) and standard Hybrid III 6YO is shown in Figure 1 The DAPRR pelvis has a more curved ASIS profile with very soft flesh in front of the bone The gel abdomen extends in front of the pelvis and up to the ribcage Conversely the HYIII 6YO abdomen is mostly contained within the pelvic cavity with only a small profile protruding above the pelvis this leaves a ldquogaprdquo between the top of the abdomen and the bottom of the ribcage In addition to the pelvis the spine box of the DAPRR was modified to include a chest deflection measurement IRTRACC in place of the rotary-type deflection potentiometer used in the HYIII 6YO

DAPRR

Improved pelvis geometry

gel abdomen

IRTRACC

HYIII 6YO

HYIII based pelvis

foam abdomen

rotary chest pot

Figure 1 Features of DAPRR Abdomen amp Pelvis Components

7 Kent R Stacey S Kindig M Forman J Woods W Rouhana S W et al (2006) Biomechanical response of the pediatric abdomen part 1 development of an experimental model and quantification of structural response to dynamic belt loading Stapp Car Crash Journal 50 1-26 8 Rouhana S W Elhagediab A M Walbridge A Hardy W N amp Schneider LW (2001) Development of a reusable rate-sensitive abdomen for the Hybrid III family of dummies Stapp Car Crash Journal 45 33-60 9 ldquoDAPRRrdquo refers to the Dummy Abdomen and Pelvis Round Robin group which has been involved in the test and development of the 6YO abdomen and pelvis

2

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 12: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

2 Methods

Both component level and dynamic sled tests were conducted on the standard Hybrid III 6-yearshyold (HYIII 6YO) and the dummy with the prototype pelvis and gel-filled abdomen (Table 1) These tests were intended to compare the responses and kinematics from each dummy In addition the tests sought to identify alternative measures of abdomen loading for use as an injury criterion in child restraint testing

Table 1 Test Modes for the HYIII 6YO and DAPRR Dummies

Test Description Test Type Number of Tests HYIII 6YO

Number of Tests DAPRR

Pendulum Impacts to Abdomen Component 10 11 Seat Belt Pull Tests Component 3 5 Sled Tests Dynamic Full Scale 12 12

21 Pendulum Impacts to Abdomen

A series of pendulum abdomen impacts ranging from 15 ms to 25 ms were conducted using the DAPRR and standard HYIII 6YO Tests were conducted at increasing energy levels in order to assess whether damage would occur to DAPRR parts The goal of the test series was comparison of the abdomen penetration between the DAPRR and HYIII 6YO Table 2 shows the test matrix for this series

Table 2 Test Matrix Abdomen Pendulum Impacts to the HYIII 6YO and DAPRR 6YO

Test Number Dummy Velocity (ms) 6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

6YOAbdoPend 15mps 26Mar2013 02 6YOAbdoPend 15mps 26Mar2013 03 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 6YOAbdoPend 15mps 20Mar2013 02 6YOAbdoPend 15mps 20Mar2013 03 6YOAbdoPend 20mps 27Mar2013 01 HYIII 6YO

20

6YOAbdoPend 20mps 28Mar2013 02 6YOAbdoPend 20mps 28Mar2013 03 6YOAbdoPend 20mps 28Mar2013 04 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 6YOAbdoPend 20mps 19Mar2013 02 6YOAbdoPend 20mps 19Mar2013 03 6YOAbdoPend 20mps 19Mar2013 04 6YOAbdoPend 20mps 19Mar2013 05 6YOAbdoPend 25mps 26Mar2013 01 HYIII 6YO

25

6YOAbdoPend 25mps 26Mar2013 02 6YOAbdoPend 25mps 26Mar2013 03 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 6YOAbdoPend 25mps 19Mar2013 02 6YOAbdoPend 25mps 19Mar2013 03

3

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 13: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

211 Methodology

For these component level tests each dummy was instrumented as shown in Table 3 Since the aim of this study was to calculate abdomen penetration the primary instrumentation used was the lower spine X acceleration and pendulum X acceleration A location for the accelerometer on the lower spine was selected so that it was approximately aligned with the line of impact from the probe Calculating the difference between the (double) integrations of these two accelerations yields abdomen penetration

Table 3 6YO Pendulum Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Light Trap X X Pendulum Acceleration X X X ASIS Upper Force (Left amp Right) X X ASIS Lower Force (Left amp Right) X X Lower Spine Acceleration X X X Pelvis Acceleration X Z X X

Because the DAPRR was not instrumented and had no bracket to hold the abdomen in place in the pelvis cavity a piece of Ethafoam was inserted between the lumbar spine and the posterior side of the abdomen (Figure 2) This helped to hold the abdomen in place while not constraining the lumbar spine from bending

Figure 2 DAPRR gel abdomen with Ethafoam inserted behind abdomen

In the tests conducted with the DAPRR the probe was directed for impact at the umbilicus (just above the pelvis) in order to avoid pelvic interference during abdomen penetration (Figure 3) A 5918 kg probe with a 1 inch diameter bar attachment was used for these tests This setup is shown in Figure 4 The probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed

4

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 14: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Pelvis edge

Figure 3 Alignment of the probe bar just above pelvis in the DAPRR

Figure 4 Setup for pendulum impacts to the DAPRR abdomen (top) probe alignment and (bottom) test setup

5

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 15: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

For the standard HYIII 6YO setup the pendulum probe bar was also aligned at the umbilicus (pelvischest jacket interface) (Figure 5) As in the DAPRR setup the probe height was set without the jacket in place so that the abdomen impact point and pelvis were visible Tests were then conducted with the jacket installed In these tests since the probe was lower relative to the table than in the DAPRR tests it was necessary to remove the feet from the dummy to prevent probe interference (Figure 6) The feet were taped to the legs to maintain mass of the lower limbs Removing the feet was not necessary on the DAPRR since the probe was positioned slightly higher for gel abdomen impact

Figure 5 Probe alignment in HYIII 6YO impacts

Figure 6 Setup for abdomen pendulum tests with the HYIII 6YO

6

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 16: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

2111 Calculating Abdomen Penetration

In order to calculate abdomen penetration the lower spine and pendulum accelerations were used All data met SAE J211 polarity specifications prior to processing The lower spine X and pendulum X accelerations were filtered with a Class CFC180 filter

The following calculations were performed to obtain the relative abdomen displacement (with respect to the spine)

Calculate the abdomen relative acceleration (with respect to the dummy spine coordinate system)

aAB = aprobe ndash aSP

Assuming that the probe velocity is instantaneously imparted to the abdomen surface at impact

VABd0 = Vprobe_at_impact

Calculating the upper abdomen relative velocity VAB = int aAB dt = aABt + C1

When t = 0 VAB = C1 = Vprobe_at_impact

VAB = aABt + Vprobe_at_impact

Calculating the abdomen relative displacement dAB = intVAB dt = int(aABt + Vprobe_at_impact ) dt

= 12 aABt2 + Vprobe_at_impactt + C2

When t = 0 C2 = d0 = 0 dAB =12 aABt2 + Vprobe_at_impactt

Where aAB = abdomen (X) acceleration (ms2) aprobe = probe (X) acceleration (ms2) asp = lower spine (X) acceleration (ms2) VABd0 = initial abdomen velocity (ms) VAB = abdomen velocity (ms) dAB = abdomen displacement (m) d0 = initial abdomen displacement (m) Vprobe_at_impact

10 = -15 ms -20 ms -25 ms C1C2 = constants of integration

10 Following J211 sign convention this velocity is negative in the calculations

7

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 17: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

212 Results and Discussion

The results of the pendulum impact series are presented in Table 4 - Table 5 and Figure 7 - Figure 9 The DAPRR response displays progressively increasing penetration with increasing impact velocity (Table 4) The HYIII 6YO penetration does not follow this trend This indicates that the DAPRR is better able to differentiate between input conditions of increasing severity

In addition to differences in abdomen penetration the force levels for the DAPRR impacts were lower compared to the HYIII 6YO (Table 5) This was anticipated since the DAPRR abdomen is much softer than the HYIII 6YO Test repeatability was good with percent coefficient of variance (CV) values for both dummies below 6 percent in all tests

Table 4 Summary of Abdomen Penetration From Pendulum Tests

Velocity (ms) HYIII 6YO Abdomen Penetration (mm)

DAPRR Abdomen Penetration (mm)

15 300 364 20 354 437 25 340 487

8

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 18: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Table 5 Results of HYIII 6YO and DAPRR Abdomen Impacts

Test Number Dummy Velocity (ms)

Max Force (N)

Mean Force (N)

Abdomen Penetration

Max Force (mm)

Mean Abdomen

Penetration

6YOAbdoPend 15mps 25Mar2013 01 HYIII 6YO

15

531 514 plusmn 12

CV = 23

304 300 plusmn 04 CV = 13

6YOAbdoPend 15mps 26Mar2013 02 509 295 6YOAbdoPend 15mps 26Mar2013 03 502 302 6YOAbdoPend 15mps 20Mar2013 01 DAPRR 382

393 plusmn 8 CV = 20

369 364 plusmn 04 CV = 11

6YOAbdoPend 15mps 20Mar2013 02 397 364 6YOAbdoPend 15mps 20Mar2013 03 400 360 6YOAbdoPend 20mps 27Mar2013 01 HYIII

6YO

20

588

638 plusmn 36 CV = 56

378

354 plusmn 20 CV = 56

6YOAbdoPend 20mps 28Mar2013 02 685 335 6YOAbdoPend 20mps 28Mar2013 03 655 332 6YOAbdoPend 20mps 28Mar2013 04 622 369 6YOAbdoPend 20mps 19Mar2013 01 DAPRR 549

560 plusmn 13 CV = 23

451

437 plusmn 09 CV = 21

6YOAbdoPend 20mps 19Mar2013 02 540 442 6YOAbdoPend 20mps 19Mar2013 03 565 429 6YOAbdoPend 20mps 19Mar2013 04 576 427 6YOAbdoPend 20mps 19Mar2013 05 568 438 6YOAbdoPend 25mps 26Mar2013 01 HYIII

6YO

25

934 920 plusmn 13

CV = 14

341 340 plusmn 01 CV = 03

6YOAbdoPend 25mps 26Mar2013 02 923 341 6YOAbdoPend 25mps 26Mar2013 03 903 338 6YOAbdoPend 25mps 19Mar2013 01 DAPRR 744

760 plusmn 12 CV = 16

49 487 plusmn 02 CV = 04

6YOAbdoPend 25mps 19Mar2013 02 771 488 6YOAbdoPend 25mps 19Mar2013 03 765 484

9

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 19: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

The stiffness of the DAPRR abdomen is not rate dependent (Figure 7) as the responses for the three test velocities followed the same curve path with small hysteresis This behavior was not expected given that the abdomen is filled with fluid that has rate dependent properties This suggests that the response is more elastic than viscous and is dictated almost completely by the abdomen shell thickness and properties while the fluid adds mass without significantly affecting the response In the HYIII 6YO impact force rises then levels off followed by a second rise (Figure 8) Films confirm that the probe first impacted the abdomen then rides up and over the top of the abdomen given the small surface area available for contact between the probe and abdomen (Figure 5) If this is indeed the scenario then the resulting penetration was not due solely to abdomen compression but was biased by the probe slipping into the gap between the top of the abdomen and thorax (see Figure 6 for orientation of the probe to this interface) The portion of the penetration related to the abdomen deflection was approximately the first 12 mm if the probe is indeed slipping into the gap

Figure 7 Pendulum force versus abdomen penetration in DAPRR pendulum impacts

10

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 20: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Pen

du

lum

Fo

rce

(N)

probe begins to ride up over top

of abdomen

jacket compression

rearward translation

of abdomen

probe constrained between top of

abdomen and thorax

Figure 8 Pendulum force versus abdomen penetration in HYIII 6YO pendulum impacts

A comparison of the average DAPRR and HYIII 6YO impact tests at each velocity is shown in Figure 9 - Figure 11 The DAPRR response is smooth it does not indicate the leveling period which is theorized to be the probe riding over the top of the abdomen occurring at approximately 12 mm of penetration at all velocities The DAPRR abdomen has a shelf on both the left and right sides that compresses into the front of the anterior superior iliac spine or ASIS (see Figure 1) which helps to reduce the risk of probe override observed in the HIII 6YO

11

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 21: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

0 10 20 30 40 50

Abdomen Penetration (mm)

0

250

500

750

1000

Pe

nd

ulu

m F

orc

e (

N)

AVG DAPRR

AVG HYIII 6YO

Pendulum Force vs Abdomen Penetration DAPRR amp HYIII 6YO 15ms Impact Tests

Figure 9 DAPRR and HYIII 6YO average force-penetration 15ms

Figure 10 DAPRR and HYIII 6YO average force-penetration 20ms

12

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 22: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 11 DAPRR and HYIII 6YO average force-penetration 25ms

Note that the DAPRR response contains very little hysteresis and almost behaves elastically This further supports the observation that the abdomen shell rather than the fluid is dictating the response The large amount of hysteresis in the HYIII 6YO response is not reflective of abdominal loading past 12 mm the probe is no longer compressing the abdomen but rather coming in contact with other parts of the dummy such as the jacket chest pot plate and lumbar joint

13

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 23: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

22 Seat Belt Pull Tests

A seat belt pull test device was originally developed by UMTRI and used for post-mortem Human Subject (PMHS) testing11 to determine force-deflection characteristics of the adult abdomen under dynamic belt loading The overall function of the seat belt test device is to provide a dynamic but controlled seat belt input for a PMHS or an ATD Both the standard HYIII 6YO and the DAPRR with gel abdomen were evaluated using this device Table 6 shows the test matrix for these tests For the DAPRR tests were conducted in both a high and low belt position (Figure 12 and Figure 13) Figure 14 illustrates the belt position for the HYIII 6YO

Figure 12 High belt position for DAPRR belt pull tests

Figure 13 Low belt position for DAPRR belt pull tests

11 Hardy W N Schneider L W amp Rouhana S W (2001 November) Abdominal impact response to rigid-bar seatbelt and airbag loading Stapp Car Crash Journal 45 1-32

14

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 24: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 14 Belt position for HYIII 6YO belt pull tests

Table 6 Seat Belt Pull Test Matrix

Test Number

Dummy Abdomen Pelvis Test Pressure

Seat Belt Location

std6yostdabd05211302 Standard

75 Centered at

pelvisabd interface

std6yostdabd05211303 HYIII 6YO

Standard Abdomen

6YO Pelvis

95std6yostdabd05211305

6yogelabddaprrpel05281301

HYIII 6YO

Gel-Filled DAPRR Pelvis

95 High6yogelabddaprrpel05281302

6yogelabddaprrpel05281303 6yogelabddaprrpel05281304

Low6yogelabddaprrpel05281305

221 Methodology

The seat belt pull device uses a pneumatic piston to thrust a seat belt into the abdomenpelvis of the dummy Air pressure can be adjusted to achieve the desired output String potentiometers (stringpots) attached to the pelvis and seat belt allow for calculation of the abdomen penetration from the belt Figure 15 and Figure 16 show the DAPRR and HYIII 6YO dummies set up for a

15

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 25: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

test in the seat belt pull device Instrumentation for the test is illustrated in Figure 17 and Figure 18

Figure 15 DAPRR 6YO in seat belt pull device

Figure 16 HYIII 6YO in seat belt pull device

16

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 26: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Belt Load Cells

Teflon surface

T-bar

Figure 17 Setup for belt pull tests showing instrumentation

Pelvis Stringpot

Belt Stringpot

T-Handle

Figure 18 Stringpot configuration for pelvis displacement measurement

17

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 27: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

The instrumentation for the belt pull tests is given in Table 7 The abdomen penetration is obtained by subtracting the displacement measurements of the pelvis stringpot from the belt stringpot Belt load cells were used to measure abdomen load These were installed away from the beltabdomen interface near both ends of the seat belt so they did not interfere during the test

Table 7 6YO Seat Belt Pull Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Seat Belt Displacement X X X Pelvis Displacement X X X Seat Belt Load (Left amp Right) X X ASIS Load (Left amp Right) X X Ram Acceleration X X X Ram Displacement X X X

The dummies were placed on Teflon low friction material on the seating surface The seat belt anchor spacing was approximately the breadth of the dummy at the belt interface position (center of belt over top edge of pelvis) The belt spacing is critical as it constrains the abdomen when the abdomen expands laterally during test Belt spacing was approximately 203 mm (8rdquo) for each dummy Lightweight foam padding was taped to the ldquoT-barrdquo between the seat belt anchors to cushion rebound

The seat belt pull device typically uses a high tension stringpot connected between the posterior pelvis and the T-bar However due to the smaller mass of the 6-year-old dummy compared to adults the high tension stringpot had a tendency to pull the pelvis rearward prior to test As a result the pelvis stringpot was reconfigured Two T-handle devices were placed into the left and right H-points on the dummy (Figure 18) A wire cable was placed on each handle with enough slack for the cable to be pulled taut at the center by the stringpot (Figure 19) The string was positioned approximately parallel to the seating surface

The belt stringpot was attached to the seatbelt by carefully passing the string through the center of the webbing then tying the string off to a lightweight button washer or similar small flat object to distribute the stringpot tension across the width of the belt and minimize localized belt deflection

18

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 28: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 19 Belt and pelvis stringpot configurations

To conduct the belt pull test the ldquoT-barrdquo (ram) was pulled to its full-out position The belt was directly against the surface of the abdomenpelvis without gapping If the stringpot tension is too high undesirable gapping could occur The belt tension was adjusted so that each belt load cell measured 15-20 N The weight of the seat belt load cells tends to turn the seat belt outwards so a piece of masking tape was lightly adhered between the two seat belt load cells to properly align the belt surface

For the seat belt pull device a 95 psi setting yields an input similar to Hardy Schneider and Rouhana A lower energy 75 psi pulse was used initially to determine damage potential to the dummies Once this lower pulse was determined to not cause damage the higher 95 psi pulse was used for the remaining tests to compare the DAPRR and HYIII 6YO responses

222 Calculating Belt Load Force Abdomen Penetration and Velocity

The following calculations summarize the steps required to process the data from the seat belt test fixture The polarities used in the test series and for the calculations below are given in Table 8

Table 8 Polarities for Seat Belt Testing and Calculations

Channel Polarity Pelvis Displacement Stringpot Positive (+) when stringpot reels out Seat Belt Displacement Stringpot Positive (+) when stringpot reels out RAMXF Positive (+) in compression RAMXG Positive (+) when ram is pushed inwards

19

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 29: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

2221 Calculating Belt Loading Force

The total belt load can be calculated from the sum of left and right belt load cells

BeltFTOT = BeltFL + BeltFR

where BeltFTOT = TOTAL Belt Force (N) BeltFL = Left Belt Load Cell Force (N) BeltFRR = Right Belt Load Cell Force (N)

2222 Calculating Abdomen Penetration

To calculate abdomen penetration the displacement of the pelvis was subtracted from the displacement of the belt

DAbd = Dbelt - Dpelvis

DAbd = Abdomen penetration (mm) Dpelvis = Displacement of pelvis (mm) (measured from pelvis

stringpot) Dbelt = Displacement of seat belt (mm) (measured from seat belt

stringpot)

2223 Calculating Abdomen Penetration Velocity

The velocity of abdomen penetration was obtained by differentiating the abdomen penetration

Vabd = ddt (DAbd)

Vabd = Abdomen penetration velocity (ms) DAbd = Abdomen penetration (m)

223 Results and Discussion

Abdomen force penetration curves were compared to the biofidelity target developed by Kent et al12 Average results for both dummies are shown in Figure 20 The HYIII 6YO was stiffer than the DAPRR and showed much less penetration (Figure 20 and Table 9) The penetration velocity of these tests ranged from 06 ms on the HYIII 6YO to a range of 27 ndash 49 ms on the DAPRR this was also characteristic of the stiffer HYIII 6YO compared to the DAPRR The DAPRR abdomen showed a smooth belt penetration then leveled and rose again This DAPRR response was consistent with HYIII pendulum tests in that there was belt slippage but the

12 Kent R W Stacey S Mattice J M Kindig M W Forman J L Woods W A amp Evans J (2006) Assessment of abdominal injury criteria for use with pediatric seatbelt loading Proceedings of the 5th World Congress of Biomechanics Munich Germany abstract in J Biomech 39(1) S159

20

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 30: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

transition was due to a different mechanism Instead of the probe moving from the abdomen into the space between the thorax and abdomen it appears that after the belt had compressed the abdomen into the ASIS portion of the pelvis up to 25- to 35 mm depending on initial belt position the belt slipped over the ASIS yet still engaged the top portion of the abdomen until near the end of the event In addition the DAPRR came closer to meeting the pediatric corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher penetration levels but similar maximum force

Load

(N

)

4mm

max penetration before belt over-ride

Biofidelity Corridor (Kent et al)

AVG HYIII 6YO

AVG DAPRR (High Belt)

AVG DAPRR (Low Belt)

Figure 20 Average load-penetrations for the belt pull tests for the HYIII 6YO and DAPRR (high and low belt placement tests) ndash all tests 95 psi

21

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 31: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Table 9 Seat Belt Pull Test Results

Test Number

Test Pressure

Seat Belt Location

Max Penetration (first peak)

(mm)

Max Force at

Max Penetration

(N)

Belt Penetration

velocity (ms)

std6yostdabd05211303 95 AbdomenPelvis Interface

4 1666 06 std6yostdabd05211305 5 1917 06 6yogelabddaprrpel05281301 95 High 37 2588 39 6yogelabddaprrpel05281302 36 2365 49 6yogelabddaprrpel05281303 33 2282 49 6yogelabddaprrpel05281304 Low 27 2564 27 6yogelabddaprrpel05281305 29 2336 27

23 Sled Tests

A series of 12 sled tests was conducted with the HYIII 6YO and DAPRR dummies on an FMVSS No 213 bench13 Table 10 shows the sled test matrix A variety of configurations were selected in order to assess abdomen penetration in various restraint conditions In general tests were conducted in order of increasing severity The first four tests were conducted at a lower energy level of 40 kmh since the DAPRR had not yet been subjected to full scale sled testing In the initial four tests each of the four restraint types were used once Both the DAPRR and HYIII 6YO showed no damage with the 40 kmh pulse therefore the remainder of tests were conducted using the standard FMVSS No 213 pulse

The 40 kmh pulse is based on a past FMVSS No 208 Occupant Crash Protection sled test condition and has been used to evaluate adult PMHS response in belted frontal sled tests14 This pulse was used as a starting pulse to assure the DAPRR durability would be sufficient before proceeding to the regulatory type FMVSS No 213 condition Both pulses are shown below in Figure 21

13 These tests used a newer stiff foam 213 bench being evaluated by NHTSA 14 Shaw G Parent D Purtsezov S Lessley D Crandall J Kent R hellip amp Martin P (2009 November) Impact response of restrained PMHS in frontal sled tests Stapp Car Crash Journal 53 pp 1-48

22

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 32: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Table 10 HYIII 6YO and DAPRR 6YO Abdomen Sled Test Matrix

Test Test Number

Booster Seat Bench Seat Pan Angle (deg)

Seat Belt Configuration

Test Pulse

Test 1 S131205-1 APEX 65 7deg 3-point 40 kmh Test 2 S131209-1 Big Kid (Backless) 7deg 3-point 40 kmh Test 3 S131209-2 Big Kid

(High Back) 7deg 3-point 40 kmh

Test 4 S131210-1 NONE 7deg 3-point 40 kmh Test 5 S131211-1 APEX 65 16deg 3-point FMVSS 213 Test 6 S131212-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 7 S131212-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 8 S131216-1 Big Kid (Backless) 16deg 3-point FMVSS 213 Test 9 S131216-2 Big Kid

(High Back) 16deg 3-point FMVSS 213

Test 10 S131217-1 NONE 16deg 3-point FMVSS 213 Test 11 S131217-2 NONE 7deg 3-point FMVSS 213 Test 12 S131217-3 NONE 7deg Lap Belt Only

(slouched) FMVSS 213

Figure 21 Exemplar medium energy (left) and high energy (right) pulses used in sled evaluation

Figure 22 to Figure 33 show the various configurations in the sled test series In the last two tests the seat pan was lowered from 16deg to 7deg to increase the likelihood of severe lap belt intrusion into the abdomen On the final test which used a lap belt only the dummy was positioned with additional ldquoslouchrdquo along with a Teflon sheet on the bench to further increase belt penetration into the abdomen

23

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 33: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 22 Sled Test 1 five-point harness

Figure 23 Sled Test 2 backless CRS

Figure 24 Sled Test 3 high back CRS

24

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 34: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 25 Sled Test 4 three-point belt only

Figure 26 Sled Test 5 five-point harness

Figure 27 Sled Test 6 backless CRS

25

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 35: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 28 Sled Test 7 high back CRS

Figure 29 Sled Test 8 backless CRS

Figure 30 Sled Test 9 high back CRS

26

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 36: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 31 Sled Test 10 three-point belt only

Figure 32 Sled Test 11 three-point belt only with 7deg seat pan angle

27

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 37: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 33 Sled Test 12 lap belt only with 7deg seat pan angle

231 Methodology

The instrumentation used in the sled series is given in Table 11 Instrumentation was similar for both dummies The main difference in instrumentation between the two was the method of chest displacement measurement The DAPRR dummy used an IRTRACC to measure chest displacement while the standard HYIII 6YO used a chest potentiometer The instrumentation in the pelvis and on the seat belt was of particular interest in this sled series since abdomen performance assessment was the primary goal In addition to the dummy instrumentation channels the seat belts were configured with an X Y Z accelerometer block and a Y-axis angular rate sensor (ARS) Examples of the seat belt motion blocks mounted for testing are shown in Figure 34 In tests using a 3-point or 2-point lap belt the accelerometers were centrally mounted to the lap belt On the 5-point harness CRS (APEX 65) the accelerometers were installed on the belt as illustrated in the bottom photo of Figure 34 These seat belt instrumentation blocks were used to calculate the motion of the seat belt In a similar manner the motion of the pelvis was obtained from the 3aω block in the pelvis (Figure 35) The belt

28

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 38: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

penetration into the abdomen was calculated from the difference in displacement between the seat belt and the pelvis

Table 11 6YO Sled Test Instrumentation

Instrumentation HYIII Standard 6YO HYIII DAPRR Pelvis amp Gel Abdomen

Head X Y Z Acceleration X X Head Angular Accel Rate X Y Z X X Neck Upper Force X Y Z X X Neck Upper Moment X Y Z X X Neck Lower Force X Y Z X X Neck Lower Moment X Y Z X X Chest Acceleration X Y Z X X Chest Angular Accel Rate X Y Z X X Chest Deflection via chest potentiometer via IR-TRACC Lumbar Force X Y Z X X Lumbar Moment X Y Z X X Pelvis Acceleration X Y Z X X Pelvis Angular Accel Rate X Y Z X X IliacASIS Upper Force (Left amp Right) X X IliacASIS Lower Force (Left amp Right) X X Shoulder Belt Force X X Lap Belt Force X X Belt Acceleration X Y Z X X Belt Angular Accel Rate Y X X

29

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 39: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 34 Examples of seat belt accelerometers and ARS

30

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 40: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 35 Pelvis motion block installed in the DAPRR dummy

232 Abdomen Penetration

In order to calculate abdomen penetration the accelerometerangular rate sensor blocks mounted on the seat belt and in the pelvis (Figure 34 and Figure 35) were used All data met SAE J211 polarity specifications prior to processing Signals from accelerometers and angular rate sensors were filtered with a Class CFC180 filter Initial orientations of the pelvis and seat belt blocks15

were recorded for each test since this information is necessary for transforming the coordinate systems of the two blocks

For this analysis a simpler 2-dimensional (rather than 3-D) approach was taken by assuming that the Y axes of both belt block and pelvis block coordinate systems were essentially parallel throughout the test The following calculations were performed to calculate relative abdomen penetration (with respect to the pelvis)

1 Using the initial orientation block measurements calculate the angles αpelvis and αbelt (in the X-Z plane) of the pelvis block and belt block coordinate systems

15 Measurements collected via FARO technology

31

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 41: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

+X+X

PELVIS

αbelt

BELTBLOCK BLOCK

+Zαpelvis+Z

2 Calculate the rotations of the pelvis (ʘpelvis) and belt (ʘbelt) during the test using the Y-axis ARS on each block

ʘpelvis = int ωYpelvis dt + αpelvis

ʘbelt = int ωYbelt dt + αbelt

3 Calculate the difference in pelvis angle and belt angle ʘdiff = ʘbelt -ʘpelvis

4 Transform the belt coordinate system into the pelvis coordinate system

Where aprimebeltX = belt (X) acceleration in pelvis coordinate system (ms2) aprimebeltZ = belt (Z) acceleration in pelvis coordinate system (ms2) abeltX = belt (X) acceleration in belt coordinate system (ms2) abeltZ = belt (Z) acceleration in belt coordinate system (ms2)

5 Calculate the abdomen relative X and Z accelerations (with respect to the pelvis coordinate system)

prime aab_pen_X = a beltX ndash apelvisXprime aab_pen_Z = a beltZ ndash apelvisZ

Where aab_pen_X = abdomen (X) penetration acceleration in pelvis coordinate system (ms2) aab_pen_Z = abdomen (Z) penetration acceleration in pelvis coordinate system (ms2) apelvisX = pelvis (X) acceleration in pelvis coordinate system (ms2) apelvisZ = pelvis (Z) acceleration in pelvis coordinate system (ms2)

6 Calculate the abdomen relative velocity Vab_pen_X = int aab_pen_X dt Vab_pen_Z = int aab_pen_Z dt

Where

32

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 42: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Vab_pen_X = abdomen (X) penetration velocity in pelvis coordinate system (ms2) Vab_pen_Z = abdomen (Z) penetration velocity in pelvis coordinate system (ms2)

7 Calculate the abdomen penetration dab_pen_X = int Vab_pen_X dt dab_pen_z = int Vab_pen_z dt

Where dab_pen_X = abdomen (X) penetration in pelvis coordinate system (ms2) dab_pen_z = abdomen (Z) penetration in pelvis coordinate system (ms2)

Because integration is involved in the calculation of abdomen penetration accumulated integration error was expected after relative motion between the belt and pelvis blocks ceased Therefore to obtain a true estimate of peak abdomen penetration the abdomen penetration velocity was used as a ldquocutoffrdquo transition between real relative motion and the beginning of accumulated integration error The time when the velocity crossed zero or the first time at which the velocity approached zero was used as the reference time at which the peak abdomen penetration was determined (Figure 36) In cases where the velocity approached but did not return to zero high speed video was analyzed to confirm that no further penetration occurred after that time and that any relative motion between the belt and pelvis occurred during rebound

Rel

ativ

e A

bd

om

en P

enet

rati

on

Vel

oci

ty (

mp

s)

25 50 75 100 125 150 175 Time (msec)

-05

-025

0

025

05

Abdomen X penetration velocity (mps)

Figure 36 Using abdomen penetration velocity as the cutoff for peak abdomen penetration measurement

Time of real peak abdomen penetration in cases where velocity did not return to zero until after rebound

Time of real peak abdomen penetration

Video analysis indicates this oscillation occurs during rebound phase

233 Results and Discussion

2331 40 kmh Sled Tests (1-4)

The first four tests in the sled series were conducted at 40 kmh in order to assess possible damage to the DAPRR dummy components since this dummy had not yet been subjected to full scale tests Although these tests are not directly comparable to FMVSS 213 Child Restraint Systems specifications which use a 48 kmh test pulse results were compared to the current FMVSS 213 IARVs for HIC (36) Chest G (3ms) head excursion and knee excursion for

33

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 43: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

informational purposes (Table 12) Data plots from Tests 1 ndash 4 are in Appendices A ndash D Peak neck and chest measurements are in Appendix M

Table 12 6YO Sled Tests 40 kmh Current 213 IARVs

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII DAPRR HYIII DAPRR HYIII DAPRR HYIII DAPRR 6YO 6YO 6YO 6YO

HIC 36 218 269 178 173 127 121 262 197 Chest G 3ms

328 372 336 383 324 372 303 346

Head Excursion (mm) 574 539

426 400 480 433 448 423

Knee Excursion 753 737 544 555 573 559 628 589 (mm)

Since sled testing focused on abdomen performance Table 13 displays measurements of interest in the abdomen pelvis and lumbar spine In Tests 2 ndash 4 the DAPRR abdomen displayed increased abdomen penetration compared to the HYIII 6YO (Figure 37) In Test 1 the HYIII 6YO abdomen penetration was much higher than expected likely due to the penetration measurement technique used on the 5-point harness Since the belt motion block is installed on the 5-point harness vertical belt (Figure 34 bottom) complications arise since the block cannot be centered on the abdomen Gapping between the belt and abdomen is more likely to occur in this scenario compared to placement of the block on a lap belt Therefore abdomen penetration data from 5-point harness tests is not a reliable indication of abdomen performance

In all test modes except for the 3-point belt without a CRS the maximum abdomen penetration occurred at maximum abdomen force In the 3-point belt test without a CRS maximum abdomen penetration occurred after maximum force This could indicate the lap belt migrating over the ASIS bones since the penetration is continuing to increase while the ASIS load is decreasing (belt is no longer on the pelvis)

Figure 37 Abdomen penetration comparison for 40 kmh tests

34

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 44: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Table 13 6YO Sled Tests 40 kmh Abdomen and Lumbar Measurements

Test 1 APEX 65

(5-Pt Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-62 -13 -15 -39 -12 -46 -13 -43

Max X Belt Penetration (mm) amp ASIS Load (N)

-76mm -336N

-13mm -314N

-15mm -1428N

-39mm -1172N

-12mm -1589N

-46mm -599N

-14mm -1514N

-45mm -1479N

Total Upper ASIS Load (N) -180 -173 -453 -407 -495 -214 -1131 -1061 Total Lower ASIS Load (N) -389 -280 -1017 -771 -1106 -436 -1114 -1210 Total ASIS Load (N) -554 -453 -1467 -1177 -1599 -649 -2246 -2271 Shoulder Belt Max Tension (N) 4082 3897 3633 4611 4082 4611 3633 3897 Lap Belt Max Tension (N) 2567 2707 2511 2560 2567 2560 2511 2707 Lumbar X Force (N)

573 674 599 661 332 657 666 653

Lumbar Z Force (N) -1902 -2025 -434 -533 -469 -851 1018 611

Lumbar Y Moment (Nm) 18 18 18 23 16 15 26 38

Max Pelvis Angle (deg) 9 NA 9 22 6 19 11 17

ARS failure ndash replaced for subsequent tests

35

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 45: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Further evidence of the higher stiffness of the HYIII 6YO abdomen compared to the DAPRR is illustrated in Figure 38 This figure shows a comparison of the total ASIS forces for both dummies In all but Test 4 the HYIII 6YO displayed greater ASIS force indicating increased abdomen stiffness Recall from Figure 1 that the DAPRR gel abdomen extends anterior to the ASIS while the HYIII 6YO abdomen is contained behind the pelvis anterior surface

Figure 38 Total ASIS force comparison for 40 kmh tests

Plots of the X penetrations of the abdomen are presented in Figure 39 - Figure 42 for each test in the 40 kmh test series Although these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) all results are presented as positive for ease of interpretation

Test 1 (Figure 39) illustrates the difficulties in using this measurement technique on a 5-point harness system as described previously In Tests 2 3 and 4 (Figure 40 - Figure 42) the X penetration is consistently larger in the DAPRR compared to the HYIII 6YO The softer abdomen allows the belt to penetrate deeper into the abdomen at a lower force level compared to the HYIII 6YO In Figure 42 the abdomen penetration does not return to zero as observed in the hysteresis unloading curves in the booster seat conditions (Figure 40 and Figure 41) As described in the methods section the end of the abdomen penetration event was taken as the time at which the abdomen penetration velocity reached zero or first approached zero prior to rearward motion of the dummy or ldquoreboundrdquo (see Appendix M) This is the point at which there is no longer relative motion between the belt and pelvis motion blocks during the frontal event This is noted as a dot on the ASIS force versus abdomen penetration plots below and dashed vertical lines on abdomen penetration versus time plots in the appendix Past this time accumulated integration error from the acceleration measurements gives false interpretation of relative motion between the belt and pelvis motion blocks This anomaly will be addressed with a more robust ldquocutoffrdquo criteria as this penetration measurement methodology is further developed

36

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 46: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 1 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 39 Total ASIS force versus X abdomen penetration for 5-point harness Test 1

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 2 - Backless BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 40 Total ASIS force versus X abdomen penetration for backless CRS Test 2

37

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 47: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

0 25 50 75 100

Abdomen Penetration (mm)

0

500

1000

1500

2000

2500

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 40 kph Test 3 - High Back BPB DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 41 Total ASIS force versus X abdomen penetration for high back CRS Test 3

To

tal A

SIS

Fo

rce

(N

) Dots indicate peak abdomen penetration

Figure 42 Total ASIS force versus X abdomen penetration for 3-point belt Test 4

38

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 48: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

2332 FMVSS 213 (48 kmh) Tests (5-12)

The remainder of the sled tests used the FMVSS No 213 48 kmh test pulse In Test 12 (lap belt configuration) the HYIII 6YO experienced an unexpected failure of the lumbar bracket causing the dummy to separate between the torso and pelvis Therefore no HYIII 6YO data is reported for Test 12

Comparison of the sled tests to the current FMVSS No 213 IARV specifications for HIC (36) Chest G (3ms) head excursion and knee excursion are presented in Table 14 and Figure 43 The chest accelerations in the DAPRR were higher in the backless booster and no CRS conditions but lower in the 5-point harness and highback booster cases These variations with restraint were likely due in part to the fact that the DAPRR uses an IRTRACC chest measurement system and the HYIII 6YO uses a rotary potentiometer that requires a heavy attachment plate at the base of the thorax Differences in boundary conditions and mass may account for variations between the chest accelerations from each dummy

Head excursions are slightly lower in the DAPRR compared to the HYIII 6YO in all restraint conditions This may be due to a greater likelihood of lap belt migration over the ASIS bones in the DAPRR because of enhancements to the pelvis and the gel-filled abdomen As the pelvis rotates and slides under the belt the upper body tends to move downward rather than translating forward resulting in increased knee excursion Interestingly a corresponding increase in the DAPRR knee excursion was not observed in the case of the backless booster In addition severe lap belt intrusion can at times lead to an increase in HIC due to limited upper body translation and a more severe head rotation resulting in a hard chin-chest contact That did not occur in this case since DAPRR HIC values were lower than the HYIII 6YO in the backless booster and no CRS cases Overall the DAPRR does not appear to significantly affect FMVSS No 213 specified measures when compared to the standard HYIII 6YO

Abdomen and lumbar measurements are presented in Table 15 and Table 16 The DAPRR abdomen allows for increased X penetration compared to the HYIII 6YO Figure 44 displays a comparison of the X abdomen penetration for both the DAPRR and HYIII 6YO for the 48 kmh tests illustrating this point The chart also shows that the DAPRR can better differentiate between various types of seat and input configurations which is consistent with previous findings when testing an early version of the DAPRR system16 In general the DAPRR showed decreasing abdomen penetration in tests where a booster seat was used This was not necessarily the case with the HYIII 6YO measurements The highback and 5-point harness had larger penetrations than one of the cases where no CRS was used

Data time histories from Tests 5 ndash 12 are in Appendices E ndash L Abdomen penetration time analysis is found in Appendix M Peak neck and chest measurements are in Appendix N

16 Klinich K D Reed M P Manary M A amp Orton N R (2010) Development and testing of a more realistic pelvis for the hybrid III 6 year old ATD Traffic Injury Prevention 11(6)606-12

39

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 49: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Table 14 6YO Sled Tests 48 kmh (FMVSS 213) Pulse Current 213 IARVs

IARV Test 5

APEX 65 CRS (5-Point harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO DAPRR

HIC 36 1000 490 500 594 543 390 356 606 502 Chest G 3ms 60

454 476 508 560 514 519 483 565

Head Excursion (mm)

813 584 554 432 395 497 441 441 411

Knee Excursion (mm)

915 771 768 570 560 600 588 571 577

IARV Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

HIC 36 1000 421 397 801 728 857 918 Dummy Failure 966 Chest G 3ms

60 551 546 443 573 474 568 Dummy Failure 51

Head Excursion (mm)

813 498 449 473 471 472 457 Dummy Failure 739

Knee Excursion (mm)

915 610 604 600 590 621 591 Dummy Failure 706

40

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 50: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Note Backless BPB results are average of Tests 6 and 8 High back BPB results are average of Tests 7 and 9

Figure 43 Comparison of the FMVSS 213 values between the standard HYIII 6YO and the DAPRR

41

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 51: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Table 15 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 5-8

Test 5 APEX 65

(5-Pt Harness) CRS

Test 6 Big Kid

(Backless) CRS

Test 7 Big Kid

(High Back) CRS

Test 8 Big Kid

(Backless) CRS

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-33 -22 -20 -42 -15 -29 -16 -48

Max X Belt Penetration (mm) amp ASIS Load (N)

-33mm

-869N

-23mm

-869N

-22mm

-2134N

-40mm

-1581N

-15mm

-2770N

-29mm

-1358N

-17mm

-1839N

-53mm

-1014N

Total Upper ASIS Load (N)

-280 -115 -913 -594 -955 -412 -843 -656

Total Lower ASIS Load (N)

-604 -242 -1788 -1054 -1861 -1012 -1558 -1099

Total ASIS Load (N)

-881 -355 -2696 -1647 -2816 -1423 -2398 -1755

Shoulder Belt Max Tension (N)

3989 4123 6143 6427 5919 6231 6015 6570

Lap Belt Max Tension (N)

4626 4521 3932 3595 3983 3381 3619 3806

Lumbar X Force (N)

809 863 1227 903 807 728 1103 951

Lumbar Z Force (N) -2974 -2806

-752 -818 -621 -855 -746 -772 1182 783 1160 366 1478 858

Lumbar Y Moment (Nm)

26 25 35 51 42 57 24 17

Max Pelvis Angle (deg) 12 21 15 25 9 25 12 30

42

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 52: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Table 16 6YO Sled Tests 48 kmh (213 Pulse) Abdomen and Lumbar Measurements Tests 9-12

Test 9 Big Kid

(High Back) CRS

Test 10 3-Point Belt

(Seatpan 16deg)

Test 11 3-Point Belt (Seatpan 7deg)

Test 12 Lap Belt

(Seatpan 7deg) HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

X Belt Penetration at Max Total ASIS Force (mm)

-30 -39 -12 -48 -21 -46 Dummy Failure

-105

Max X Belt Penetration (mm) amp ASIS Load (N)

-31mm

-2109N

-39mm

-1516N

-12mm

-3096N

-44mm

-3053N

-26mm

-2438N

-53mm

-1443N

Dummy Failure

-117mm

-514N

Total Upper ASIS Load (N)

-845 -577 -1516 -1584 -1802 -1919 Dummy Failure

-201

Total Lower ASIS Load (N)

-1893 -1035 -1772 -1797 -1782 -1893 Dummy Failure

-455

Total ASIS Load (N)

-2763 -1612 -3340 -3881 -3584 -3805 Dummy Failure

-655

Shoulder Belt Max Tension (N)

6271 6259 5149 5611 5340 5689 Dummy Failure

NA

Lap Belt Max Tension (N)

3869 3826 3731 4381 4083 4506 Dummy Failure

NA

Lumbar X Force (N)

944 912 1328 1194 1379 1374 Dummy Failure

3318

Lumbar Z Force (N)

-622 -883 1454 1171 1653 1380

Dummy Failure 5533

1318 613 Lumbar Y Moment (Nm)

24 34 35 51 42 57 Dummy Failure

-36 52

Max Pelvis Angle (deg) 13 27 13 25 20 34

Dummy Failure -58

43

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 53: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 44 Abdomen penetration comparison for 48 kmh tests

Figure 45 - Figure 52 present plots of the ASIS force versus abdomen X penetrations for each test in the 48 kmh test series As in the 40 kmh tests these measurements are set up in the SAE J211 coordinate system (relative to the dummyrsquos pelvis) but results are presented as positive for ease of interpretation As seen in Test 1 of the 40 kmh data using the motion block measurement technique on the 5-point harness in the 48 kmh test (Test 5 Figure 45) was again problematic Therefore abdomen penetration data from 5-point harness Test 5 is not a reliable indication of abdomen performance In the remaining tests Figure 46 - Figure 52 the abdomen X penetrations are consistently larger in the DAPRR compared to the HYIII 6YO indicating that the HYIII 6YO is much stiffer than the DAPRR Note again in some cases the continuing increase in penetration after the ASIS begins to unload

During the test series it was discovered that the top of the abdomen was ldquorolling outrdquo of the pelvis evidence of this movement was discovered after Test 7 in this series (Figure 53) Since this abdomen was a non-instrumented prototype without an attachment bracket to fix the abdomen to the pelvis base the abdomen was contained by the jacket anteriorly the ASIS bones laterally and the lumbar joint posteriorly For subsequent tests in order to minimize abdomen movement within the pelvis cavity a small piece of closed-cell foam was placed between the posterior bottom of the abdomen and the lumbar spine In addition the abdomen was taped over the top and along the sides of the pelvis to hold it in place (Figure 54) This technique was not ideal but somewhat effective in maintaining the abdomen within the pelvis for the remaining tests in this series The booster seat test conditions in Tests 6 amp 7 were repeated in Tests 8 amp 9 to account for possible effects of abdominal rollout on the DAPRR penetration values Design of an abdomenpelvis interface bracket is desired to stabilize the abdomen in future testing

44

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 54: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

0 25 50 75 100

Abdomen Penetration (mm)

0

1000

2000

3000

4000

To

tal A

SIS

Fo

rce

(N

)

Abdomen X Penetration (mm) DAPRR

Abdomen X Penetration (mm) HYIII 6YO

Total ASIS Force vs Abdomen Penetration 48 kph Test 5 - 5-Point Harness DAPRR amp HYIII 6YO

Dots indicate peak abdomen penetration

Figure 45 Total ASIS force versus X abdomen penetration for 5-point harness Test 5

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 46 Total ASIS force versus X abdomen penetration for 3-point belt Test 6

45

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 55: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 47 Total ASIS force versus X abdomen penetration for high back CRS Test 7

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 48 Total ASIS force versus X abdomen penetration for backless CRS Test 8

46

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 56: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 49 Total ASIS force versus X abdomen penetration for high back CRS Test 9

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 50 Total ASIS force versus X abdomen penetration for 3-point belt (16deg) Test 10

47

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 57: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

To

tal

AS

IS F

orc

e (N

)

Dots indicate peak abdomen penetration

Figure 51 Total ASIS force versus X abdomen penetration for 3-point belt (7deg) Test 11

To

tal

AS

IS F

orc

e (N

) Dots indicate peak abdomen penetration

Figure 52 Total ASIS force versus X abdomen penetration for lap belt (7deg) Test 12

48

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 58: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Top anterior portion of abdomen extends past front of ribcage

Figure 53 Top of abdomen ldquorolling outrdquo of pelvis

Figure 54 Using tape to hold abdomen in place to minimize ldquorolling outrdquo

Increased pelvis rotation can indicate a greater tendency for lap belt intrusion into the abdomen17 The DAPRR displayed different pelvis rotations compared to the HYIII 6YO The chart in Figure 55 shows that the DAPRR pelvis rotated more than the HYIII 6YO in all tests There was an increased pelvic rotation from Test 10 to Test 11 for both dummies These tests were identical except for the seat pan angle which was lowered from 16deg to 7deg in an attempt to increase the severity of lap belt intrusion Based on pelvis rotation results lap belt intrusion did increase with a decrease in seat pan angle Note that a rearward (counterclockwise looking at ATD right side) pelvis rotation is indicated in the positive direction In Test 12 the lap belt test the pelvis rotated forward (negative) since the upper torso was not restrained

17 Rouhana S Horsch J amp Kroell C (1989) Assessment of lap-shoulder belt restraint performance in laboratory testing (SAE Technical Paper 892439) Warrendale PA Society of Automotive Engineers

49

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 59: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 55 Pelvis rotation (about pelvic Y axis) comparison chart

The total ASIS loads are illustrated in Figure 56 In most cases the HYIII 6YO shows greater ASIS loading than the DAPRR This indicates that the pelvis rather than the abdomen may be experiencing increased loading The abdomen is in front of the ASIS in the DAPRR while the abdomen fits behind the pelvis skin in the HYIII 6YO this may contribute to loading differences In addition increased ASIS load is also indicative of the HYIII 6YO abdomen being much stiffer than the DAPRR

To verify that the abdomen penetrations from the sled tests are accurate correlations between component level belt pull tests and full-scale sled tests were investigated The total ASIS force versus abdomen X penetration was plotted for each test scenario Figure 57 shows this comparison for the 3-point belt sled test (Test 10) Since the sled test is a higher energy test the peak force in the sled test is much greater as expected However the force-penetration curves follow the same shape to the maximum force in the belt pull tests These results indicate that the measured penetrations from the sled tests are accurate and that it may be possible to use ASIS load to predict abdomen penetration in a sled test The technique of using the motion block on the seat belt to determine abdomen penetration shows promise with refinement This preliminary study shows that this technique could lead to an alternative measurement technique of abdomen penetration and loading for use as an injury criterion in future FMVSS No 213 testing

50

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 60: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Figure 56 Total ASIS load comparison for 48 kmh tests

consistent behavior in this

area

Figure 57 Comparison of total ASIS load versus abdomen penetration for belt pull and three-point

51

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 61: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

3 Conclusions

The HYIII 6YO and DAPRR 6YO dummies were tested in pendulum impacts belt pull tests and sled tests Overall for all test modes the DAPRR tended to display more abdomen penetration at lower force levels The HYIII 6YO was stiffer allowing much less penetration and higher intrusion force

Impact tests conducted with both dummies were repeatable However the impact bar tended to over-ride the top of the HYIII 6YO abdomen resulting in little actual abdomen compression The DAPRR showed more penetration with increasing test rate stiffness was independent of test rate despite the presence of viscous material within the abdomen structure The outer shell appears to be the most critical factor in dictating the abdomen response

In the belt pull tests abdomen force-penetration curves were compared to the pediatric biofidelity target The HYIII 6YO was stiffer than the DAPRR and showed much less penetration In addition the DAPRR came closer to meeting the biofidelity corridor than the HYIII 6YO Results from the high and low belt placement tests on the DAPRR indicate that the high placement yielded slightly higher force levels but similar overall maximum penetration

Sled tests indicated that the DAPRR was more sensitive to different types of restraints than the HYIII 6YO Evidence of this was found in increased abdomen penetration and pelvis rotation as the test configuration moved from booster to non-booster cases An alternative method for calculating abdomen penetration in the 6YO was developed and the results were encouraging based on similarity in ASIS force versus abdomen penetration responses between belt pull component tests and sled testing In a few tests the DAPRR abdomen moved out of position from the pelvic cavity A method for better stability of the abdomen within the pelvis is necessary to prevent this from occurring in future tests While some differences were observed between the FMVSS No 213 injury assessment reference values (IARVs) measured by the two dummies overall these measurements were not significantly altered by DAPRR design changes The chest acceleration differences between ATDs tended to vary with restraint and these differences were likely due to DAPRR thorax-abdomen interface differences Head excursions were slightly lower in the DAPRR possibly due to increased propensity for the lap belt to migrate over the ASIS bones which often corresponds to less upper body forward translation

In summary the DAPRR package improves the sensitivity of the HYIII 6YO ATD to kinematic conditions associated with abdominal injury The abdomen and pelvis appear to be more sensitive to incremental changes in restraint and lap belt intrusion than the current ATD

Ongoing work includes refinement of abdomen penetration measurement and stabilization of the abdomen within the pelvis If an instrumented version of the gel abdomen becomes available in the future repeat tests will be done with the instrumented version to compare with the results from this report This study presents initial work based on a prototype dummy For this dummy to become a useful tool for measuring abdomen penetration and loading as an injury criterion in future FMVSSS No 213 testing the following would need to be realized

The abdominal penetration measurement technique will need to be refined to be both practical and robust for CRS testing

52

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 62: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

The dummy andor abdomen components will need to be modified to ensure the abdomen can be stabilized within the dummy

Component qualification test procedures will need to be improved to eliminate phenomena associated with test probebelt slippage

A more robust cutoff criterion for abdomen penetration will need to be developed

53

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 63: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX A Test 1 Plots (40 kmh 5-point Harness)

Ch

est

Acc

eler

atio

n (

G)

54

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 64: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

0 50 100 150 200

Time (msec)

-500

0

500

1000

1500

2000

2500

3000

3500

4000

HYIII 6YO Lap Belt Load

HYIII 6YO Shoulder Belt Load

DAPRR Lap Belt Load

DAPRR Shoulder Belt Load

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

55

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 65: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

56

Lu

mb

ar Y

Mo

men

t (N

m)

Up

per

Nec

k Y

Mo

men

t (N

m)

Ch

es

t D

efl

ec

tio

n (

mm

)

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 66: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

Pel

vis

Y R

ota

tio

n (

deg

)

57

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 67: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX B Test 2 Plots (40 kmh Backless Booster)

58

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 68: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

59

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 69: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

60

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 70: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

61

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 71: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX C Test 3 Plots (40 kmh Highback Booster)

62

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 72: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

63

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 73: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

64

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 74: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

65

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 75: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX D Test 4 Plots (40 kmh No CRS)

66

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 76: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

67

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 77: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

68

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 78: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

69

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 79: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX E Test 5 Plots (48 kmh 5-Point Harness)

70

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 80: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

71

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 81: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

72

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 82: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

73

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 83: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX F Test 6 Plots (48 kmh Backless Booster)

74

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 84: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

75

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 85: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

76

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 86: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

77

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 87: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX G Test 7 Plots (48 kmh Highback Booster)

78

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 88: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

79

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 89: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

80

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 90: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

81

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 91: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX H Test 8 Plots (48 kmh Backless Booster)

82

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 92: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

83

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 93: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

84

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 94: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

85

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 95: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX I Test 9 Plots (48 kmh Highback Booster)

86

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 96: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

87

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 97: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

88

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 98: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

89

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 99: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX J Test 10 Plots (48 kmh No CRS)

90

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 100: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

91

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 101: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

92

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 102: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

93

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 103: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX K Test 11 Plots (48 kmh No CRS 7deg Bench Angle)

94

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 104: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

95

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 105: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

96

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 106: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Dashed vertical lines indicate cutoff times for abdomen penetration calculation

97

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 107: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Pel

vis

Acc

eler

atio

n (

G)

Hea

d A

ccel

erat

ion

(G

)

AS

IS L

oad

(N

) C

hes

t A

ccel

erat

ion

(G

)

APPENDIX L Test 12 Plots (48 kmh No CRS Lap Belt 7deg Bench Angle) Note Only DAPRR plots are shown since the HYIII 6YO experienced failure

98

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 108: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

99

Up

per

Nec

k F

orc

es (

N)

Lu

mb

ar F

orc

es (

N)

Lo

wer

Nec

k F

orc

es (

N)

Seat belt loads not available

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

DOT HS 812 088 January 2015

11089-010515-v4a

Page 109: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

Lu

mb

ar Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

-40

-30

-20

-10

0

10

20

30

Up

per

Nec

k Y

Mo

men

t (N

m)

DAPRR Upper Neck Y Moment

DAPRR Lower Neck Y Moment

5

25

0

-25

-5

-75

-10

-125

-15

DAPRR Chest Deflection

Ch

est

Def

lect

ion

(m

m)

0 50 100 150 200

Time (msec)

-60

-40

-20

0

20

40

Lo

wer

Nec

k Y

Mo

men

t (N

m)

0 50 100 150 200

Time (msec)

100

0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

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0 50 100 150 200

Time (msec)

-250

-200

-150

-100

-50

0

Ab

do

men

X P

enet

rati

on

(m

m)

DAPRR X Abdomen Penetration

Pel

vis

Y R

ota

tio

n (

deg

)

Dashed vertical line indicates cutoff times for abdomen penetration calculation

101

APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

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APPENDIX M Abdomen Penetration Analysis

Test Dummy

Relative Belt (X) Penetration

Velocity Closest to

Zero (mps)

Time of Zero

Velocity Belt Penetration

(msec)

Abdomen Penetration at Zero Velocity

Belt Penetration (mm)

TOTAL ASIS force at Zero Velocity Belt Penetration

(N)

Test 1 HYIII 6YO -075 9872 -76 -336

DAPRR 0 7328 -13 -314

Test 2 HYIII 6YO 0 6632 -15 -1428

DAPRR 0 6792 -39 -1172

Test 3 HYIII 6YO 0 5872 -12 -1589

DAPRR 0 6784 -46 -599

Test 4 HYIII 6YO -009 6592 -14 -1514

DAPRR -012 6600 -45 -1479

Test 5 HYIII 6YO 0 6736 -33 -869

DAPRR 0 6664 -23 -340

Test 6 HYIII 6YO -024 5144 -22 -2134

DAPRR -097 4792 -40 -1581

Test 7 HYIII 6YO 0 4056 -15 -2770

DAPRR 0 4456 -29 -1358

Test 8 HYIII 6YO -0094 5096 -17 -1839

DAPRR -058 5776 -53 -1014

Test 9 HYIII 6YO 0 492 -31 -2109

DAPRR 0 4896 -39 -1516

Test 10 HYIII 6YO 0 4192 -12 -3096

DAPRR -1205 3952 -44 -3053

Test 11 HYIII 6YO -028 4808 -26 -2438

DAPRR 0 5584 -53 -1443 Test 12 DAPRR 0 6472 -117 -514

102

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

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Page 112: Comparative Evaluation of 6-Year-Old Hybrid III and DAPRR ......biofidelic abdomen and pelvis components could therefore improve the prediction of abdomen injury when using the 6-year-old

APPENDIX N Neck Loads and Chest Compression

40 kmh Tests

Test 1 APEX 65

(5-Point Harness) CRS

Test 2 Big Kid

(Backless) CRS

Test 3 Big Kid

(High Back) CRS

Test 4 3-Point Belt

HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR HYIII 6YO

DAPRR

Peak Upper Neck X Load (N) -464 -475 -439 -427 -384 -394 -460 -463 Peak Upper Neck Z Load (N) 1259 1425 1660 1070 1081 1082 2318 1636 Peak Chest Compression (mm) -123 -110 -331 -261 -283 -229 -149 -134

48 kmh Tests

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N) Peak Chest Compression (mm)

Peak Upper Neck X Load (N)

Peak Upper Neck Z Load (N)

Peak Chest Compression (mm)

Test 5 APEX 65

(5-Point Harness) CRS HYIII 6YO

DAPRR

-563 -598

1777 2256

-139 -109

Test 9 Big Kid

(High Back) CRS HYIII 6YO

DAPRR

-611 -563

2627 1655

-356 -280

Test 6 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-581 -612

3431 2246

-354 -272

Test 10 3-Point Belt

(Seatpan 16deg)

HYIII

6YO DAPRR

-666 -694 504 743

4355 3593

-267 -302

Test 7 Big Kid

(High Back) CRS

HYIII

6YO DAPRR

-568 -560

2451 1496

-326 -267

Test 11 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

-669 -668 516 1117

4482 4526

-234 -289

Test 8 Big Kid

(Backless) CRS

HYIII

6YO DAPRR

-606 -598

3411 2278

-358 -333

Test 12 3-Point Belt (Seatpan 7deg)

HYIII

6YO DAPRR

Failure -482 Failure 444

Failure 2255

Failure -137

103

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