Crash Testing and Evaluation of the Eccentric Loader Terminal (ELT) · 2017. 1. 4. · evaluation criteria. The ELT, with two minor design modifications (replacing the standard line

Technical Report Documentation PaRe

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No.

4. Title and Subtitle

CRASH TESTING AND EVALUATION OF THE ECCENTRIC LOADER TERMINAL (ELT)

7. Author(s)

King K. Mak, Roger P. Bligh and Wanda L. Menges 9. Perfonning Organization Name and Address

Texas Transportation Institute The Texas A&M University System College Station, Texas 77843-3135 12. Sponsoring Agency Name and Address

Minnesota Department of Transportation Transportation Building 395 John Ireland Boulevard St. Paul, Minnesota 55155

15. Supplementary Notes

Contacting technical representative for Minnesota DOT: 16. Abstract

5. Report Date

March 1999 6. Perfonning Organization Code

8. Perfonning Organization Report No.

RF473390-01 10. Work Unit No. (TRAIS)

11. Contract or Grant No.

RF473390-01 13. Type of Report and Period Covered

Final Report August 1998 - October 1998 14. Sponsoring Agency Code

Glenn Korfhage, Design Standards Engineer

The Minnesota Department of Transportation (MnDOT) sponsored a study to crash test the Eccentric Loader Terminal (ELT) to determine if this device meets the criteria set forth in NCHRP Report 350. The ELT was successfully crash tested in accordance with requirements set forth in NCHRP Report 230. However, previously the Federal Highway Administration (FHW A) has required that, starting October 1998, all new installations of traffic barriers and terminals on the National Highway System (NHS) must meet the evaluation criteria of NCHRP Report 350. Therefore, it became necessary to establish if the ELT will satisfy these criteria to permit its continued use by MnDOT. The objective of this project was to determine whether the ELT meets the evaluation criteria of NCHRP Report 350.

After consultation with FHW A, it was agreed that only two of the five crash tests set forth under NCHRP Report 350 requirements - pickup truck head-on and redirection tests - would be required to qualify the ELT. FHW A waived the requirement for the pickup truck reverse direction test and would accept the two small car tests previously conducted under NCHRP Report 230 guidelines if these two tests are shown to have met all NCHRP Report 350 evaluation criteria.

The ELT, with two minor design modifications (replacing the standard line post at post 7 with a CRT post and using a lateral offset of 660 mm at post 2 instead of 635 mm), is judged to have successfully met all requirements and evaluation criteria set forth in NCHRP Report 350, including the two pickup truck crash tests conducted under this study and the two small car crash tests previously conducted under NCHRP Report 230 requirements.

17. KeyWords 18. Distribution Statement

Guardrails, terminals, end treatments, crash cushions, crash testing, roadside safety

No restrictions. This document is available to the public through NTIS:

19. Security Clas sif. (of this report)

Unclassified Form DOT F 1700.7 (8-?2)

National Technical Information Service 5285 Port Royal Road Springfield, Virginia 22161

20. Security Classif.(ofthis page)

Unclassified Reproduction of completed page authorized

21. No. of Pages

88 22. Price

SI* (MODERN METRIC) CONVERSION FACTORS

APPROXIMATE CONVERSIONS TO SI UNITS APPROXIMATE CONVERSIONS FROM SI UNITS

Symbol When You Know Multiply by To Find Symbol Symbol When You Know Multiply by To Find Symbol

LENGTH LENGTH

In Inches 25.4 millimeters mm mm millimeters 0.039 inches in ft feet 0.305 meters m m meters 3.28 feet ft

yd yards 0.914 meters m m meters 1.09 yards yd ml miles 1.61 kilometers km km kilometers 0.621 miles mi

AREA AREA

In2 square inches 645.2 square millimeters mm2 mm2 square millimeters 0.0016 square inches in2

ft2 square feet 0.093 square meters m2 m2 square meters 10.764 square feet ft2 yd2 square yards 0.836 square meters m2 m2 square meters 1.195 square yards yd2

ac acres 0.405 hectares ha ha hectares 2.47 acres ac mi2 square miles 2.59 square kilometers km2 km2 square kilometers 0.386 square miles mi2

VOLUME VOLUME

floz fluid ounces 29.57 milliliters mL mL milliliters 0.034 fluid ounces floz gal gallons 3.785 liters L L liters 0.264 gallons gal ft3 cubic feet 0.028 cubic meters m3 m3 cubic meters 35.71 cubic feet ft3

yd3 cubic yards 0.765 cubic meters m3 m3 cubic meters 1.307 cubic yards yd3

..... ..... NOTE: Volumes greater than 1000 I shall be shown In m3 •

MASS MASS

oz ounces 28.35 grams g g grams 0.035 ounces oz Ib pounds 0.454 kilograms kg kg kilograms 2.202 pounds Ib T short tons 0.907 megagrams Mg Mg megagrams 1.103 short tons T

(2000Ib) (or "metric ton") (or "t") (or "t") (or "metric ton") (2000Ib)

TEMPERATURE (exact) TEMPERATURE (exact)

OF Fahrenheit 5(F-32)J9 or Celcius °C °C Celclus 1.8C+32 Fahrenheit OF temperature (F-32)J1.8 temperature temperature temperature

ILLUMINATION ILLUMINATION

fc foot-candles 10.76 lux Ix Ix lux 0.0929 foot-candles fc fl foot-Lamberts 3.426 candelalm2 cdlm2 cd/m2 candelalm2 0.2919 foot-Lamberts fl

FORCE and PRESSURE or STRESS FORCE and PRESSURE or STRESS

Ibf poundforce 4.45 newtons N N newtons 0.225 poundforce Ibf I bfli n2 poundforce per 6.89 kllopascals kPa kPa kllopascals 0.145 poundforce per I bfll n2

square inch square inch

*SI Is the symbol for the International System of Units. Appropriate (Revised September 1993) rounding should be made to comply with Section 4 of ASTM E380.

TABLE OF CONTENTS

I. INTRODUCTION .......................................................... 1 1.1 BACKGROUND ............................................... 1 1.2 OBJECTIVES/SCOPE OF RESEARCH ............................. 1

1.2.1 Establish Required Crash Test Matrix ......................... 2 1.2.2 Construct Test Installation ................................... 2 1.2.3 Perform Required Crash Tests ................................ 2 1.2.4 Evaluate Crash Test Results .................................. 2 1.2.5 Report Study Results and Findings ............................ 3

II. STUDY APPROACH ...................................................... 5 2.1 TEST FACILITY ................................................. 5 2.2 TEST ARTICLE - DESIGN AND CONSTRUCTION .................. 5 2.3 TEST CONDITIONS ............................................ 13 2.4 EVALUATION CRITERIA ....................................... 14

III. CRASH TEST RESULTS ................................................. 17 3.1 CRASH TEST 473390-1 (NCHRP REPORT 350 TEST 3-35) ............ 17

3.1.1 Test Vehicle ............................................... 17 3.1.2 Soil and Weather Conditions ................................ 17 3.1.3 Impact Description ......................................... 20 3.1.4 Damage to Test Article ..................................... 20 3.1.5 Vehicle Damage ........................................... 20 3.1.6 Assessment of Test Results .................................. 24

3.2 CRASH TEST 473390-2 (NCHRP REPORT 350 TEST 3-31) ............ 27 3.2.1 Test Vehicle ............................................... 27 3.2.2 Soil and Weather Conditions ................................ 31 3.2.3 Impact Description ......................................... 31 3.2.4 Damage to Test Article ..................................... 32 3.2.5 Vehicle Damage ........................................... 32 3.2.6 Assessment of Test Results .................................. 32

IV. ANALYSIS OF COMPARABLE NCHRP REPORT 230 TESTS ................. 41 4.1 CRASH TEST RBCT-13 (NCHRP REPORT 350 TEST 3-30) ........... 41

4.1.1 Test Descriptions .......................................... 41 4.1.2 Assessment of Test Results .................................. 42

4.2 CRASH TEST RBCT-19 (NCHRP REPORT 350 TEST 3-34) ........... 43 4.2.1 Test Descriptions .......................................... 43 4.2.2 Assessment of Test Results .................................. 44

iii

TABLE OF CONTENTS (continued)

V. CONCLUSIONS AND RECOMMENDATIONS ............................... 47 5.1 SUMMARY OF FINDINGS ....................................... 47 5.2 CONCLUSIONS AND RECOMMENDATIONS ...................... 51

APPENDIX A. CRASH TEST PROCEDURES AND DATA ANALYSIS ............. 55 ELECTRONIC INSTRUMENTATION AND DATA PROCESSING .......... 55 ANTHROPOMORPHIC DUMMY INSTRUMENTATION .................. 56 PHOTOGRAPHIC INSTRUMENTATION AND DATA PROCESSING ....... 56 TEST VEHICLE PROPULSION AND GUIDANCE ........................ 56

APPENDIX B. TEST VEHICLE PROPERTIES AND INFORMATION ............. 57

APPENDIX C. SEQUENTIAL PHOTOGRAPHS ................................ 63

APPENDIX D. VEHICLE ANGULAR DISPLACEMENTS AND ACCELERATIONS ............................................... 71

REFERENCES .............................................................. 81

iv

Figure No.

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 21

22

23

24

25 26

27

28

29 30

31

LIST OF FIGURES

Details of the Minnesota ELT ................. 0 0 . 0 0 0 0 0 0 .... 0 0 0 0 0 0 0 .. 0 6 Layout of test installation . 0 0 0 0 0 • 0 0 • 0 0 0 0 0 0 •. 0 0 .••. 0 •.. 0 ... 0 0 0 0 0 0 .. 0 . 0 11 Minnesota ELT prior to testing .. 0 .• 0 0 0 0 .•. 0 •. 0 0 0 0 .• 0 ... 0 0 0 0 . 0 0 0 •• 0 .. 12 Vehicle/installation geometrics for test 473390-1 000 ... 0 0 0 0 0 • 0 . 0 . 0 0 0000 .• 18 Vehicle before test 473390-1 00.0 .. 0 ... 0 0 0 0 • 0 .• 0 . 0 0 0 0 0 0 . 0 0 . 0 0000 ..... 19 Vehicle trajectory path after test 473390-1 •.•.... 0 0 0 . 0 0 . 0 .. 0 0 0 0 . 0 ... 0 0 • 21 Installation after test 473390-1 0 0 . 0 0 .. 0 .. 0 • 0 0 0 0 0 0 •. 0 .. 0 •.. 0 ... 0 0 0 0 .•. 22 Vehicle after test 473390-1 00 •.. 0 0 ... 0 0 0 .•. 0 • 0 ..• 0 ....•.. 0 0 •......•• 23 Interior of vehicle for test 473390-1 0 •.. 0 ... 0 0 • 0 .. 0 .....•....•.. 0 0 0 0 •. 25 Summary of results for test 473390-1, NCHRP Report 350 test 3-35 .0 .... 0 .. 26 Minnesota ELT installation before test 473390-2 •. 000 .. 00 ... 0 0 . 0 ......•. 28 Vehicle/installation geometrics for test 473390-2 0 . 0 ... 0 0 0 0 0 ..... 0 0 0 0 .• 0 .29 Vehicle before test 473390-2 ..••. 00 .. 0 . 0 0 .. 0 ... 0 0 ..•. 0 0 . 0 0 0 ... 0 ... 0 030 Vehicle trajectory path after test 473390-2 0 •.•.. 0 0 •...•.... 0 . 0 .. 0 . 0 0 •.. 33 Installation after test 473390-2 0 0 .•.. 0 •. 0 • 0 ••..••. 0 0 ..•..•. 0 0 0 ••..•. 0 34 Vehicle after test 473390-2 ...•..•...•.. 0 .•.. 0 ••...•.•. 0 •. 0 0 ..• 0 .• 0 .35 Interior of vehicle for test 473390-2 ...•. 0 . 0 • 0 . 0 • 0 . 0 .. 0 • 0 .•.•. 0 0 0 . 0 •.. 36 Summary of results for test 473390-2, NCHRP Report 350 test 3-31 .. 0 •..• 0 . 37 Vehicle properties for test 473390-1 000 ..•. 0 .. 0 0 ••...•.• 0 .•... 0 .• 0 0 0 .• 57 Vehicle properties for test 473390-2 ..•. 0. 0 0 .... 0 . 0 0 •. 0 •..•.• 0 .••.. 0 .. 60 Sequential photographs for test 473390-1 (overhead and frontal views) .. 0 0 •..•• 0 ...•. 0 . 0 . 0 ..• 0 0 0 .. 0 .• 0 0 • 0 .•... 63 Sequential photographs for test 473390-1 (rear view) .. 0 .... 0 •.•.. 0 •.... 0 0 • 0 ...... 0 0 • 0 ...•. 0 •. 0 ..•. 0 •• 0 0 0 .. 65 Sequential photographs for test 473390-2 (overhead and frontal views) 0 0 .... 0 . 0 .. 0 .•. 0 .. 0 0 . 0 0 ... 0 0 0 .•..•.. 0 0 .. 66 Sequential photographs for test 473390-2 (rear view) 0 0 • 0 • 0 .•.... 0 •...•..•.. 0 0 ......... 0 0 ....... 0 •..••.•... 68 Vehicular angular displacements for test 473390-1 '0' .... 0.0 ...•..•. 0 •... 72 Vehicle longitudinal accelerometer trace for test 473390-1 (accelerometer located at center of gravity) ..... 0 •••••••••• 0 •••••••••••• 73 Vehicle lateral accelerometer trace for test 473390-1 (accelerometer located at center of gravity) ......... 0 •••••••• 0 •••••••••• 74 Vehicle vertical accelerometer trace for test 473390-1 (accelerometer located at center of gravity) '0, ...... 0 0 ....... 0 0 ...•..... 75 Vehicular angular displacements for test 473390-2 0 ...... 0' ....•..••. 0 ... 76 Vehicle longitudinal accelerometer trace for test 473390-2 (accelerometer located at center of gravity) .... 0 • 0 0 .. 0 .... 0 0 0 .• 0 . 0 • 0 0 0 . 077 Vehicle lateral accelerometer trace for test 473390-2 (accelerometer located at center of gravity) ....... 0 ••••••••••••••••••••• 78

v

Figure No.

32

Table No.

1

2

3

4

5 6 7 8

LIST OF FIGURES (continued)

Vehicle vertical accelerometer trace for test 473390-2 (accelerometer located at center of gravity) ............................. 79

LIST OF TABLES

Performance evaluation summary for test 473390-1, NCHRP Report 350 test 3-35 ........................................ 49 Performance evaluation summary for test 473390-2, NCHRP Report 350 test 3-31 ......................................... 50 Performance evaluation summary for test RBCT -13, NCHRP Report 350 test 3-30 ....................................... 53 Performance evaluation summary for test RBCT-19, NCHRP Report 350 test 3-34 ........................................ 54 Exterior crush measurements for test 473390-1. . ........................ 58 Occupant compartment measurements for test 473390-1 .................. 59 Exterior crush measurements for test 473390-2 ......................... 61 Occupant compartment measurements for test 473390-2 .................. 62

vi

I. INTRODUCTION

1.1 BACKGROUND

The Minnesota Department of Transportation (MnDOT) was interested in testing the Eccentric Loader Terminal (ELT), which was the primary guardrail end treatment used by MnDOT, to determine if this device meets the criteria set forth in National Cooperative Highway Research Program (NCHRP) Report 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features. (1) The ELT was successfully crash tested in accordance with requirements set forth in NCHRP Report 230.(2) However, since that time, the Federal Highway Administration (FHW A) has adopted NCHRP Report 350 as the guideline for establishing the crashworthiness of highway hardware and terrain features. It is unknown how the ELT, while satisfying the requirements of NCHRP Report 230, will perform under this new crash testing criteria.

Since the FHW A has required that, starting October 1998, all new installations of traffic barriers and terminals on the National Highway System (NHS) meet the testing and evaluation criteria of NCHRP Report 350, it becomes necessary to establish if the ELT will satisfy those criteria to permit its continued use by MnDOT.

1.2 OBJECTIVES/SCOPE OF RESEARCH

The objective of this project was to determine whether the ELT meets the evaluation criteria of NCHRP Report 350.

The scope of the work consisted of the following major tasks:

1. Establish the required crash test matrix,

2. Construct a test installation of the ELT in accordance with MnDOT design standards,

3. Perform the required crash tests,

4. Evaluate the crash test results in accordance with criteria set forth in NCHRP Report 350, and

5. Report the study results and findings.

Brief descriptions of these major tasks undertaken in the study are presented in the following sections.

1

1.2.1 Establish Required Crash Test Matrix

Under this task, the project staff: (1) reviewed all previous crash tests performed on the ELT to assess if any of the previous tests may be considered equivalent to tests currently required under NCHRP Report 350; (2) developed a proposed crash test matrix; (3) prepared and submitted a letter to FHW A requesting pre-approval of the proposed crash test matrix; and (4) worked with FHW A to reach a decision on the recommended crash test matrix.

Upon consultation with FHW A, it was agreed that only two pickup truck crash tests (head-on and redirection) would be required to qualify the ELT under NCHRP Report 350 requirements. FHW A would waive the pickup truck reverse direction test and accept the results of the two small car crash tests previously conducted under NCHRP Report 230 guidelines if the test results are shown to have met the evaluation criteria set forth in NCHRP Report 350. More details on the proposed crash test matrix and the underlying rationale and the agreement by FHW A on the recommended crash test matrix can be found in Chapter IT, Section 2.3.

1.2.2 Construct Test Installation

Materials necessary for the construction of the test installation were purchased from Trinity Industries. Upon receipt of the materials, the test installation was constructed in accordance with standard design plans provided by MnDOT except for one design modification at post 7.

The test installation consisted of 30.5 m of standard G4(2W) guardrail with wooden posts and blockouts with an ELT terminal on the impact end and an extruder terminal (LET) on the opposite end, for a total installation length of 53.3 m. Details of the installation are presented in Chapter IT, Section 2.2. The design modification involved replacing the first standard line post at post 7 with a CRT post. FHW A recommended the design modification based on test results with the Modified Eccentric Loader Terminal (MELT). The project staff concurred with the recommendation and MnDOT agreed to incorporate this modification into their ELT design.

1.2.3 Perform Required Crash Tests

The two crash tests required by FHW A to qualify the ELT were performed in accordance with procedures set forth in NCHRP Report 350. Detailed descriptions of these tests are presented in Chapter ID. The test procedures followed in this study are presented in appendix A.

1.2.4 Evaluate Crash Test Results

Details and descriptions of the evaluation criteria set forth in NCHRP Report 350 are presented in Chapter IT, Section 2.4. The two crash tests performed by TTl were analyzed and evaluated in accordance with these evaluation criteria and the results are presented in Chapter ID.

2

Results of the two small passenger car tests previously performed by Southwest Research Institute(3) under NCHRP Report 230 guidelines were also evaluated in accordance with NCHRP Report 350 guidelines and the results are presented in Chapter IV.

1.2.5 Report Study Results and Findings

This report presents the study results, findings, conclusions, and recommendations. The study approach is summarized in Chapter ll. Descriptions and results of the two crash tests performed by TTl are presented in Chapter ill while Chapter IV provides descriptions and results of the two crash tests previously conducted by Southwest Research Institute. A summary of the findings, conclusions and recommendations are presented in Chapter V.

3

II. STUDY APPROACH

2.1 TEST FACILITY

The test facilities at the Texas Transportation Institute's Proving Ground consist of a 2000-acre complex of research and training facilities situated 16 km northwest of the main campus of Texas A&M University. The site, formerly an Air Force Base, has large expanses of concrete runways and parking aprons well suited for experimental research and testing in the areas of vehicle performance and handling, vehicleroadway interaction, durability and efficacy of highway pavements, and safety evaluation of roadside safety hardware. The site selected for placing of the Minnesota ELT was at the end of a wide expanse of concrete aprons which were originally used as parking aprons for military aircraft. These aprons consist of unreinforced jointed concrete pavement in 3.8 m by 4.6 m blocks nominally 203-305 rom deep. The aprons and runways are about 50 years old and the joints have some displacement, but are otherwise flat and level. The ELT was installed on flat, level terrain in NCHRP Report 350 standard soil at the edge of the apron (as shown in the adjacent photo).

2.2 TEST ARTICLE - DESIGN AND CONSTRUCTION

Figure 1 shows the standard drawings of the current Minnesota Eccentric Loader Terminal (ELT) design. Descriptions of the major components of the ELT design are presented as follows.

The terminal is 11.4 m long, consisting of three 3.8-m sections of W -beam rail elements and seven posts. The first two posts are 140 rom x 191 rom wooden breakaway-pests-placed-infoundation tubes to ensure proper breaking of the posts. These posts were weakened with a 64-rom diameter hole at the base. Posts 3 through 7 are wooden 152 rom x 203 rom CRT posts. Two 89-rom diameter holes are drilled into a CRT post, one at ground line and the other at 406 rom below surface, to facilitate fracture of the post upon impact.

Note that the current Minnesota ELT design, as shown in the standard drawings, has post 7 as the first standard line post. As mentioned previously, the ELT design was modified for the NCHRP Report 350 compliance testing by replacing the standard line post at post 7 with a CRT post. The rationale for this design modification was that, in the pickup truck redirection test with the Modified Eccentric Loader Terminal (MELT), which has the same post arrangement as the ELT, the pickup truck snagged on post 7 and subsequently rolled over. By replacing the standard line post at post 7 with a CRT post, it is believed that the potential for snagging would be reduced and the impact performance of the terminal would be enhanced.

5

VI

~~ ..,!:! f01.., ;n .... f01C'l Z,. n-< f01-o

Z

2 SPACES AT 1.9 m = 3.8 m

LENGTH or NEED ®

3:1 OR fLATTER t 3 SPACES'AT 1.21 m = 3.8 m

POS T B. BLOCK B - 4 PLACES -- .... ---TRANSITION TO

ANY SLOPE

--- --------

,/

SLOPE 4:\ OR fLAT TtR t

NOSE

---------------

prlCAL 0ARORAIlJ

--- -------------~-~

NO.8 t NO.1'" ::I NO.6 I 10:1 SLOPt I

NOTE:

( MAX.)

Standard line post 7 was replaced with a CRT post.

11.4 m BCT fLARt LENGTH Of BCT

PLAN VIEW

ELEVATION

NOTES:

NO.3 ,

THRU BEAM

355

DIRECTION Of TRAffiC

SHELf ANGLE POST NO.2 ONLY

10:1 SLOPE (MAX.)

I. SEE" A GUIDE TO STANDARDIZED HIGHWAY BARRIER RAIL HARDWARE ",rOR ADDIT 10NAL HARDWARE INfORMATION. THE MN/DOI STANDARD SPEClflCA Tln~r fOR HIGHWAY CONSTRUCTION SHALL GOVERN.

® ECCENTRIC lOADER BCT - PAY ITEM LENGTH IS 11.4 METERS.

® LENGTH-Of -NEED BEGINS 3.8 METERS fROM BCT NOSE.

@ TANGENT GUARDRAil SHOWN. SEE CHAPTER 10 IN ROAD DESIGN MANUAL fOR PARABOLIC fLARE APPLICATIONS.

I NOTE: ALL DIMENSIONS ARE IN MILLIMETERS. EXCEP~ __ AS NOTED. I

~ ..... (JQ

~ ~

0 0 ~

8. ,...... 00

~ 90 0

--..l ~ ..... S 0 t:I'.l 0 ~

~

~ .-(") 0 ::s p".

8 8-':-'

UI6 X 2 HEX 801. T AND NUt TOP VIEW 560 mm LONe WHICH PASSES TtflU END SPLICE BOt. T SLOTS or PLATE BUU. 45 mm X 15 I11III RECTANGUlAR WASH[R AND 45 .- 0.0. IASKRS ON TOP AND BOTTOM ------..

.. 1& X 2 H[X. BOll AND NUT ZlO I11III

LONG WI1N 110 45 mm 0.0. WASHERS

SIDE VIEW

NOSE DETAILS

.,,, x 2 X 455 /111ft lG. aulTON H[AD BOI. T AND NUT C DOCS NOl GO THROUGH PLA 1E BEAU I

ELEVATION - NOSE ASSEMBLY

SHOWN LEGS OOWN. rOR OPPOSITE HAND. INS' ALL LEGS tJt

.,20 X 2.5 OIA. X 250 Le. N[X BOll 1 NUT 1mH 2-IASHERS

............................................................. u ....................................................... u .................. _ ................................. _ ...... n .. .

PLAN VIEW

STRUT AND YOKE ASSEMBLY

NOTES: CORRUGATED S TUL PIPE AS PtR SPEC. 3226. SlRlM:llRAL ST[[L AS PER SPEC. 3lO6. UN..ESS OTHERWIS[ HOlED. GALVANIZE STRUCTURAl STEEL AS PER SPEC. 3392 • 3,,4 ArTER rABRICATlON.lH.[SS OTHERWISE NOTED.

INOTE: ALL DIMENSIONS ARE IN MILLIMETERS. EXCEPT AS NOTEO.I

rt. 140 140 MEASURED ON OUTER

CIRCUMFERENCE

z~----------~~--+---+---+---~--~ ~ 0 ... 5: u w VI

w 0-CL E E o ;jj -J <[ z :i ~~----------,~~--~+-~~~-'

610 mm DIA. X 16 GAGE CORRUGATED STEEL PIPE WITH ANNULAR CORRUGATIONS

CORRUGATED STEEL PIPE

o ;:;; - --

0 .... N

I. 300

STRUCTURAL TUBE

32

250

ANGLE

315 6

~l II I T 1='. ----'1 I

STEEL PLATE (4 REQUIRED )

~j-W

32

STEEL PLATE WASHER

88

ANGLE

,i'::::::::::::··:::::::::::::··::::::::::::::::::::::-"

I==g g

:: :: o :: :: N :!::::::::::::::::::::::::::::::::::::::::::::::,::::~~

TOP VIEW

STEEL PLATE 4 REQUIRED

tJ SIDE VIEW

., o a: 0-

o o 'Q"

W6 X 9.0 OR W6 X 8.5

o .... N

19--""",(" TYP.

ECCENTRIC LOADER ASSEMBLY

1'7r:l-:f -+- RAD·-t.:..3.

51 20B I

TOP VIEW

YOKE

F ~

22 mm X

I 0 25 SO mm SlOT

SIDE VIEW

(2 REQUIRED )

<D 00 NOT USE FLAME CUTTING FOR THESE OPENINGS.

NOTE: ALL DIMENSIONS ARE IN MILLIMETERS. EXCEPT AS NOTED.

~&£~ STATE or MINNESOTA

OEPARTMENT or TRANSPORTATION SPECIrJCA nON

RErERENCE STANDARD

PLATE NO.

~ DIRECTOR

OFFICE OF TECHNICAL SUPPORT

ECCENTRIC LOADER BREAKAWAY CABLE TERMINAL (ELT)

MISCELLANEOUS NOSE DETAILS

Figure 1. Details of the Minnesota ELT (continued).

8

2554 M8329F SHEET 3 O. 4

t ~T -

22 rnm OIl.. l • HOLES

II" T5 8 X 6 i -t. lC 0.18T5

15 1S

E

150 rnm Ie 2Cl5 mm )Ii 1.1 m POST (MODlrJEO AS SHOWN AND PRESERVATIVE TAEA TED ArTER DRILLING)

230

STEEL TUBE (POST A ) WOOD BREAKAWAY POST B

20 mm OIl.. 3 • HOLts

~20 mm OJA. HOLE

~tt'l i I I!~!l

· ~J3"2:n: 150 X 205 X 355 BLOCK .

WOOD BLOCK B C STANDARD 8LOCKOUT )

610

150 230

I . G:I---

SOIL PLATE (POST A ) (2 RECUIRED I

ffll50

1S

I

] 6 """ STEEL PLAT[

WOOD BREAKAWAY POST A SHELF ANGLE CONE RECUIRED I

] ~==~~=::=:~:~-~~~=~=~==~=~ ,. I 1.71 III I

END VIEW PLAN VIEW

STRUT NOTE:

TOP

21 ",m OIl.. HOLE BEARING PLATE

ALL OIMENSIONS ARE IN MILLIMETERS. EXCEPT AS NOTED.

;?YEP£: • DIRECTOR

OFFICE OF TECHNICAL SUPPORT

STATE OF MINNESOTA DEPARTMENT or TRANSPORTATION ECCENTRIC LOADER

BREAKAWAY CABLE TERMINAL (ELT) PO';T ANn c::.TDlIT nr:TATI C

SPECIFICA nON REF'ERENCE

2554

Figure 1. Details of the Minnesota ELT (continued).

9

STANDARD PLATt

NO.

M8329F

A post spacing of 1.9 m is used with the first two spans, i.e., between posts 1 and 3, followed by three spans of 1.27-m post spacing between posts 3 and 6. The standard 1.9-m post spacing is then used beginning at post 6.

A flared offset of 1.2 m is used with the ELT. Starting with the maximum offset of 1.2 m at post 1, the offset is gradually reduced until it reaches zero (0) or tangent at post 8. The offset for posts 1 through 7 are shown on sheet 1 of figure 1. Note that the offset for post 2 is 660 mm for the Minnesota design (as crash tested in this study) instead of the 635 mm used in the original NCHRP Report 230 design shown in the test report(3) and the FHW A Technical Advisory T5040.25, "W-Beam Guardrail End Treatments", dated January 7,1986.(4)

The W -beam rail element is bolted at post 1 and post 7 with an unsupported length of 9.6 m between these posts. A shelf angle is used at post 2 to provide additional vertical support to the rail element near the cable anchor.

The nose of the ELT has a fabricated structural steel lever surrounded by a vertical section of corrugated steel pipe, details of which are shown in sheets 2 and 3 of figure 1. The end anchorage system is similar to that of the Breakaway Cable Terminal (BCT). Two 152 mm x 203 mm x 1.52 m long steel foundation tubes connected with a ground channel strut provide the required anchorage capacity. The cable anchorage assembly is attached to the W-beam rail element at one end and anchored to the wooden end post and foundation tube through a hole in the base of the post.

The test installation consisted of 30.5 m of standard G4(2W) guardrail with wooden posts and blockouts, an ELT terminal (11.4 m long) at the impact end, and an extruder terminal (15.2 m long) at the opposite end, for a total installation length of 57.1 m. Figure 2 shows a schematic of the test installation. Photographs of the test installation are shown in figure 3.

The G4(2W) guardrail consisted of 3.8-m sections of 12-gauge W -beam rail elements mounted on 1625-mm long, 150 mm x 205 mm wooden posts spaced at 1.9 m center to center, with 150 mm x 205 mm x 355 mm long wooden blockouts. The W -beam rail elements and wood blockouts are attached to the posts with 16-mm diameter button head bolts. No washers were used under the head of the bolts on the W-beam rail side. The height to the center of the W -beam rail element is 550 mm.

Note that MnDOT uses straight W-beam rail elements for the ELT, while some States use a pre-curved rail element for the first section. To form the curve for the terminal, the straight rail element is pushed into place against the posts and bolted at post 1. Due to the sharp curvature at post 2, the rail element is either kinked at post 2 (this happened in the installation for the first test - test no. 473390-1), or post 2 is pushed back laterally by the rail such that the post is leaning at an angle (this happened in the installation for the second test - test no. 473390-2). Also, ripples in the rail element were observed at various locations throughout the terminal for both test installations.

10

GUARDRAIL EXTRUDER

(

~ I I ~ ~ ~ ~ ~ ~ ( ~2 3 4 5 6 7 8

........ No.1

........

L"4 .I. .I. m BCT FLARE 30.5 m TYPICAL GUARDRAIL -----+-----------15.2 EXTRUDER TERMI NAL ---------1

r-CRT POST A ---J.~-CRT POST B-----1

J r-1905---r-1905i3 space @ 12701 2 spaces @ 1905 ,1905119051190511905119051 1905 1905 1905 905 1905

Figure 2. Layout of test installation.

Figure 3. Minnesota ELT prior to testing.

2.3 TEST CONDITIONS

According to guidelines presented in NCHRP Report 350, a total of up to five crash tests may be required for evaluation of a flared guardrail terminal under test level 3 (TL-3) conditions, which are listed as follows:

1. Test 3-30: An 820-kg passenger car impacting the terminal end-on at a nominal impact speed and angle of 100 kmIh and 0 degree with the quarter point of the vehicle aligned with the centerline of the nose of the terminal. This test is intended primarily to evaluate occupant risk and vehicle trajectory criteria.

2. Test 3-31: A 2000-kg pickup truck impacting the terminal end-on at a nominal impact speed and angle of 100 kmIh and 0 degree with the centerline of the vehicle aligned with the centerline of the nose of the terminal. This test is intended primarily to evaluate occupant risk and vehicle trajectory criteria.

3. Test 3-34: An 820-kg passenger car impacting the terminal at a nominal impact speed and angle of 100 kmIh and 15 degrees mid-point between the end of the terminal and the beginning of the length-of-need. This test is intended primarily to evaluate occupant risk and vehicle trajectory criteria.

4. Test 3-35: A 2000-kg pickup truck impacting the terminal at a nominal impact speed and angle of 100 kmIh and 20 degrees at the beginning of the length-of-need. This structural adequacy test is intended to evaluate the ability of the device to contain and redirect the 2000-kg vehicle.

5. Test 3-39: A 2000-kg pickup truck impacting the terminal at a nominal impact speed and angle of 100 kmIh and 20 degrees mid-point between the nose and the end of the terminal in the reverse direction. This test is intended to evaluate the performance of a terminal for a "reverse" hit.

After consultation with FHW A, it was agreed that only two of the five crash tests, tests 3-31 and 3-35, were necessary to qualify the ELT under NCHRP Report 350 guidelines. FHW A waived the pickup truck reverse direction test (NCHRP Report 350 test 3-39) because this test has been shown in previous crash tests to be a non-discriminating test for flared terminals.

The two small car tests (NCHRP Report 350 tests 3-30 and 3-34) were successfully performed under NCHRP Report 230 guidelines. These tests are generally considered equivalent to those required under NCHRP Report 350 since the test conditions are the same except for the slightly higher impact speed of 100 kmIh versus 96.5 kmIh. Results of these two tests are presented in Chapter IV together with an assessment of whether these tests meet evaluation criteria set forth in NCHRP Report 350. If FHW A agrees that these previous crash tests satisfactorily meet the evaluation criteria set forth under NCHRP Report 350, FHW A may waive

13

the requirements for these two tests.

In summary, while guidelines set forth in NCHRP Report 350 specify up to five crash tests for evaluation of a flared guardrail terminal under TL-3 conditions, it was agreed by FHW A that, pending review of the results of the two small passenger cars previously conducted under NCHRP Report 230 guidelines, only two crash tests, test designations 3-31 and 3-35, are needed to qualify the ELT under NCHRP Report 350 guidelines.

The crash test and data analysis procedures were in accordance with guidelines presented in NCHRP Report 350. Brief descriptions of these procedures are presented in appendix A.

2.4 EVALUATION CRITERIA

The crash tests performed were evaluated in accordance with the criteria presented in NCHRP Report 350. As stated in NCHRP Report 350, "Safety performance of a highway appurtenance cannot be measured directly but can be judged on the basis of three factors: structural adequacy, occupant risk, and vehicle trajectory after collision." Accordingly, the following safety evaluation criteria from table 5.1 of NCHRP Report 350 were used to evaluate the crash tests reported herein:

• Structural Adequacy

A. For test 3-30,3-31 and 3-34: Test article should contain and redirect the vehicle; the vehicle should not penetrate, underride, or override the installation although controlled lateral deflection of the test article is acceptable.

C. For test 3-35 only: Acceptable test article performance may be by redirection, controlled penetration, or controlled stopping of the vehicle.

• Occupant Risk

D. Detached elements, fragments or other debris from the test article should not penetrate or show potential for penetrating the occupant compartment, or present an undue hazard to other traffic, pedestrians, or personnel in a work zone. Deformation of, or intrusions into, the occupant compartment that could cause serious injuries should not be permitted.

F. The vehicle should remain upright during and after collision although moderate roll, pitching and yawing are acceptable.

H. For test 3-30, 3-31 and 3-34: Occupant impact velocities should

14

satisfy the following:

Longitudinal and Lateral Occupant Impact Velocity - mls Preferred Maximum

9 12

1. For test 3-30. 3-31 and 3-34: Occupant ridedown accelerations should satisfy the following:

Longitudinal and Lateral Occupant Ridedown Accelerations - g's Preferred Maximum

15 20

• Vehicle Trajectory

K. After collision it is preferable that the vehicle's trajectory not intrude into adjacent traffic lanes.

L. For test 3-35 only: The occupant impact velocity in the longitudinal direction should not exceed 12 mls and the occupant ridedown acceleration in the longitudinal direction should not exceed 20 g's.

M. For test 3-35 only: The exit angle from the test article preferably should be less than 60 percent of the test impact angle, measured at time of vehicle loss of contact with the test device.

N. For test 3-30. 3-31 and 3-34: Vehicle trajectory behind the test article is acceptable.

15

III. CRASH TEST RESULTS

A total of two crash tests, listed in chronological order, were perfonned on the ELT in accordance with the crash test matrix discussed in the previous chapter:

1. Test no. 473390-1 (NCHRP Report 350 test 3-35) - Pickup truck redirection test at beginning of length-of-need, and

2. Test no. 473390-2 (NCHRP Report 350 test 3-31) - Pickup truck head-on test.

Details and descriptions of these two crash tests are presented in this chapter.

3.1 CRASH TEST 473390-1 (NCHRP REPORT 350 TEST 3-35)

The fIrst test involved a 2000-kg pickup truck impacting the terminal at a nominal impact speed and angle of 100 kmIh and 20 degrees at the beginning of the length-of-need, which was selected to be at post 3 or 3.8 m from the nose of the terminal. This test corresponds to test 3-35 of the NCHRP Report 350 crash test matrix for terminals. Photographs of the installation are shown in fIgure 3. Recall that the ELT design was modifIed by replacing the standard line post at post 7 with a CRT post. Also, the lateral offset for post 2 was 660 mm instead of 635 mm as specifIed in the original ELT design.

3.1.1 Test Vehicle

A 1994 Chevrolet 2500 pickup truck, shown in fIgures 4 and 5, was used for the crash test. Test inertia weight of the vehicle was 2000 kg, and its gross static weight was 2000 kg. The height to the lower edge of the vehicle front bumper was 425 mm and the height to the upper edge of the front bumper was 640 mm. Additional dimensions and infonnation on the vehicle are given in appendix B, fIgure 19. The vehicle was directed into the installation using the cable reverse tow and guidance system, and was released to be free-wheeling and unrestrained just prior to impact.

3.1.2 Soil and Weather Conditions

The crash test was perfonned the morning of September 7,1998. Only a trace of rain was recorded for the ten days prior to the test. Moisture content of the NCHRP Report 350 standard soil in which the ELT was installed was 6.6 percent, 6.7 percent, and 5.4 percent at posts 3, 5, and 7, respectively. Weather conditions at the time of testing were as follows: Wind Speed: 8 kmIh; Wind Direction: 0 degrees with respect to the vehicle (vehicle was traveling in a northerly direction); Temperature: 32°C; Relative Humidity: 48 percent.

17

The reference for 1 wind direction is 90 0

vehicle fixed as

'hOW"·EE~ "'--~r:= '''"' 180

12700

Figure 4. Vehicle/installation geometries for test 473390-1.

18

Figure 5. Vehicle before test 473390-1.

19

3.1.3 Impact Description

The vehicle impacted the terminal 50 mm upstream of the centerline of post 3 at an impact angle of 21.0 degrees relative to the tangent section of the guardrail, traveling at a speed of 102.1 kmIh. Shortly after impact, posts 3 and 4 moved and, at 0.027 s, post 1 moved. At 0.042 s, post 4 fractured at ground level. Post 5 moved at 0.051 s and post 6 moved at 0.066 s. Post 5 fractured at ground level at 0.068 s and post 7 moved at 0.097 s. The right front tire contacted post 5 at 0.117 s and post 6 fractured at 0.130 s. At 0.148 s, post 8 moved and, at 0.161 s, the rail element started to tear at the splice at post 6. Post 7 fractured at 0.225 s and the right front tire contacted post 7 at 0.276 s. At 0.292 s, the vehicle was traveling parallel with the installation and was traveling at a speed of 69.6 kmIh. The vehicle snagged on post 8 as it began to exit the guardrail installation at 0.404 s. The front of the vehicle lost contact with the rail element at 0.490 s. At 0.746 s, the rear of the vehicle lost contact with the rail and the vehicle was traveling at a speed of 35.9 kmIh and at an exit angle of 18.8 degrees. As the vehicle exited the rail, it yawed clockwise and subsequently came to rest 20.9 m down from the initial point of impact and 3.0 m from the face of the guardrail at post 14. No braking was applied during the entire test sequence. Sequential photographs of the test period are shown in appendix C, figures 21 and 22.

3.1.4 Damage to Test Article

The ELT sustained damage from post 3 through post 8 as shown in figures 6 and 7. The foundation tubes for posts 1 and 2 were pulled forward longitudinally for 25 mm. Posts 2 and 3 were pushed back laterally 30 mm and 65 mm, respectively. Posts 4 through 7 fractured at or just below ground level. Post 8 was pushed back laterally 60 mm. The rail element was tom 180 mm at the second splice (i.e., at post 6 or 7.6 m from the nose of the terminal) from the bottom edge of the rail to a point past the second row of splice bolts. At the third splice (i.e., at post 8 or 11.4 m from the nose of the terminal), the rail element was tom over three-quarters of its depth (270 mm) from the bottom edge of the rail to the top row of splice bolts. The rail element was also kinked at post 9 and the blockouts at posts 8 through 10 were twisted. The downstream anchor did not move. The vehicle was in contact with the rail element from post 3 to a point 130 mm past post 8, for a total length of 9.63 m. Maximum dynamic deflection during the test was 0.99 m at post 7 and maximum permanent deformation was 0.64 m at post 5.

3.1.5 Vehicle Damage

As shown in figure 8, the vehicle sustained moderate damage. Structural damage was sustained by the right front frame member, right upper and lower A -arms, right rod ends, stabilizer bar, idler arm, right front spring and shock, floor pan and firewall. A cut, measuring 85 mm long by 5 mm wide, was found in the transmission tunnel. The front bumper, hood, fan, radiator, right front quarter panel, and right door were deformed. Maximum exterior crush of the

20

Figure 6. Vehicle trajectory path after test 473390-1.

21

tv tv

Figure 7. Installation after test 473390-1.

Figure 8. Vehicle after test 473390-1.

23

vehicle was 440 mm at the front right comer at bumper height. Maximum deformation into the occupant compartment was 33 mm (36 percent reduction of space) in the front center floor pan area. The interior of the vehicle is shown in figure 9. Exterior vehicle crush and occupant compartment measurements are shown in appendix B, tables 5 and 6.

3.1.6 Assessment of Test Results

A summary of the test results is presented in figure 10. Vehicle angular displacements and accelerations versus time traces are presented in appendix D, figures 25 through 28. The test results were assessed in accordance with the evaluation criteria set forth in NCHRP Report 350 for test 3-35, as described in Chapter II, Section 2.4.


A. The ELT contained and redirected the vehicle. The vehicle did not penetrate, underride, or override the installation. Maximum dynamic deflection was 0.99 m and maximum permanent residual deformation was 0.64m.

The ELT is judged to have satisfactorily met the structural adequacy criterion for this test. However, the severe tears in the rail elements at the two splices indicate that the rail element was at or near capacity for this test.

• Occupantltisk

D. Detached elements, fragments or debris did not penetrate nor show potential to penetrate the occupant compartment. The fractured posts 4 through 7 were strewn in various places covering an area 26.6 m down from the point of impact and 25.9 m behind the rail. Maximum deformation of the occupant compartment was 33 mm (36 percent reduction of space); however, since the location is in the front center floor pan area, it was judged not to cause any serious injury.

F. The vehicle remained upright during and after the collision period.

The ELT is judged to have satisfactorily met the occupant risk criteria for this test.


K. The vehicle did not intrude into adjacent traffic lanes as it came to rest adjacent to the guardrail.

L. Data from the tri-axial accelerometer, located at the vehicle center of gravity, were digitized to compute occupant impact velocity and ridedown

24

Before test

After test

Figure 9. Interior of vehicle for test 473390-1.

25

tv General Information 0\ Test Agency ............ .

Test No ................ . Date .................. .

Test Article Type .................. . Name ................. . Installation Length (m) .... . Material or Key Elements .. .

Soil Type and Condition .... Test Vehicle

Type .................. . Designation ............ . Model ................. . Mass (kg)

Curb ................ . Test Inertial .......... . Dummy ............. . Gross Static .......... .

Texas Transportation Institute 473390-1 09/07/98

Terminal Minnesota EL T 57.1 1.2 m Flared W-beam guardrail on wooden posts spaced 1.9 m Standard Soil, Dry

Production 2000P 1994 Chevrolet 2500 pickup truck

2071 2000 No dummy 2000

Impact Conditions Speed (km/h) ................ 102.1 Angle (deg) ................. 21.0

Exit Conditions Speed (km/h) . . . . . . . . . . . . . . .. 35.9 Angle (deg) ................. 18.8

Occupant Risk Values Impact Velocity (m/s)

x-direction ................ 7.3 y-direction ................ 4.5

THIV (km/h) ................ 24.4 Ridedown Accelerations (g's)

x-direction ................ -9.7 y-direction ................ -9.0

PHD (g's) . . . . . . . . . . . . . . . . . .. 12.8 ASI ....................... 0.78 Max. 0.050-s Average (g's)

x-direction ................ -6.0 y-direction ................ -5.2 z-direction ................ 7.5

Test Article Deflections (m) Dynamic ............... " 0.99 Permanent ............. " 0.64

Vehicle Damage Exterior

VDS .................. 01RFQ4 CDC . . . . . . . . . . . . . . . . .. 01 FREK2

&01RFEW3 Maximum Exterior

Vehicle Crush (mm) .... " 440 Interior

OCDI ................. RF0104000 Max. Occ. Com part.

Deformation (mm) ....... 62 Post-Impact Behavior

(during 1.0 s after impact) Max. Yaw Angle (deg) ...... -45 Max. Pitch Angle (deg) . . . . .. -5 Max. Roll Angle (deg) ..... " -6

Figure 10. Summary of results for test 473390-1, NCHRP Report 350 test 3-35.

accelerations. Note that only the occupant impact velocity and ridedown acceleration in the longitudinal axis are required for evaluation of this criterion. In the longitudinal direction, occupant impact velocity was 7.3 mls at 0.185 s, which is less than the preferred limit of 9 mls. The maximum 0.010-s ridedown acceleration was -9.7 g's from 0.385 to 0.395 s, which is less than the preferred limit of 15 g's. The maximum 0.050-s average was -6.0 g's between 0.080 and 0.130 s.

M. The exit angle at loss of contact was 18.8 degrees (90 percent of the impact angle) which was considerably more than the limit of 60 percent of the impact angle (12.6 degrees). However, upon exit from the rail, the vehicle yawed clockwise toward the installation and came to rest 3.0 m toward traffic lanes.

The ELT did not meet criterion M for exit angle. However, this criterion is considered preferable and not required. Thus, the ELT is judged to have satisfactorily met the vehicle trajectory criteria for this test.

In summary, this test is judged to have satisfactorily met all evaluation criteria set forth in NCHRP Report 350. However, given the severe tears at the two splices of the terminal, this test would be considered a marginal pass.

3.2 CRASH TEST 473390-2 (NCHRP REPORT 350 TEST 3-31)

The second test involved an end-on impact by a 2000-kg pickup truck at a nominal speed and angle of 100 kmIh and 0 degree (relative to the tangent section of the guardrail) with the centerline of the vehicle aligned with the center of the end post. This crash test corresponded to test 3-31 of the NCHRP Report 350 crash test matrix for terminals.

Photographs of the test installation are shown in figure 11. As in the previous test, post 7 of the ELT crash tested was a CRT post and not a standard line post, and the lateral offset for post 2 was 660 mm.

3.2.1 Test Vehicle

A 1994 Chevrolet 2500 pickup truck, shown in figures 12 and 13, was used for the crash test. Test inertia weight of the vehicle was 2000 kg, and its gross static weight was 2000 kg. The height to the lower edge of the vehicle front bumper was 425 mm and the height to the upper edge of the front bumper was 635 mm. Additional dimensions and information on the vehicle are given in appendix B, figure 20. The vehicle was directed into the installation using the cable reverse tow and guidance system, and was released to be free-wheeling and unrestrained just prior to impact.

27

tv 00

Figure 11. Minnesota ELT installation before test 473390-2.

Figure 12. Vehicle/installation geometries for test 473390-2.

29

Figure 13. Vehicle before test 473390-2.

30

3.2.2 Soil and Weather Conditions

The crash test was performed the morning of September 9,1998. No rainfall was recorded for the ten days prior to the test. Moisture content of the NCHRP Report 350 standard soil in which the ELT was installed was 3.9 percent, 4.4 percent, and 4.3 percent at posts 1, 3, and 5, respectively. Weather conditions at the time of testing were as follows: Wind Speed: 18 kmIh; Wind Direction: 15 degrees with respect to the vehicle (vehicle was traveling in a northerly direction); Temperature: 32°C; Relative Humidity: 59 percent.

3.2.3 Impact Description

The reference for t wind direction is 90· vehicle fixed as

shown. {E1t)--'---Th __ 0' ~J'-I8O'

r 270· .

The vehicle impacted the ELT at a speed of 99.7 kmIh. Impact angle was 0 degree relative to the tangent section of the guardrail with the centerline of the vehicle aligned with the centerline of the end post. Shortly after impact, the nose section and post 1 moved. The left side of the front bumper deformed outward at 0.017 s after impact and the rail element moved away from post 3 at 0.032 s. At 0.037 s, the rail element moved away from post 4 and the left side of the bumper contacted the nose section. The rail element moved away from post 5 at 0.037 and from post 6 at 0.039 s. Post 1 fractured at 0.040 s and the rail element moved away from post 2 forming an elbow near post 3 at 0.047 s. At 0.073 s, the front left side of the bumper of the vehicle was pushed downward, caught the left front tire and forced the tire into the wheel well. The vehicle began to pitch upward with the front wheels coming off the ground at 0.081 s.

The nose section of the ELT contacted post 2 at 0.084 s, causing the post to move longitudinally. Post 2 fractured at 0.102 s and the rail element pulled away from post 7 at 0.123 s. Speed of the vehicle at this time was 79.7 kmIh. The vehicle started to roll clockwise at 0.137 s as the nose section became lodged under left front of the vehicle. The fractured portion of post 2 contacted post 3 at 0.157 s and moved post 3 longitudinally. Post 3 was then fractured at 0.197 s. The vehicle started to yaw counterclockwise at 0.224 s. At 0.229 s, the elbow which had formed near post 3 reached a maximum deflection of 2.75 m toward the traffic lanes. Posts 4 and 5 fractured at 0.269 sand 0.327 s, respectively. At 0.366 s, the vehicle rode up the nose section and began to roll and pitch significantly. The vehicle was traveling at 74.5 kmIh at this time. Post 6 fractured at 0.396 s. Post 7 fractured at 0.542 s.

By 0.760 s, the left front tire reached the top of the rail element just before it reached post 8. The clockwise roll of the vehicle stabilized at 0.860 sec. The vehicle then contacted the top of the rail again at 0.924 s just beyond post 10. The tire slid off the top of the rail element toward the front of the rail and the vehicle straddled the installation. As the vehicle continued to travel forward, it fractured posts 11 through 25 and scattered debris along its path. Brakes on the vehicle were not applied and the vehicle subsequently came to rest 250 mm from post 26 (or 45.5 m from the point of impact which was the nose of the terminal), straddling the installation. Sequential photographs of the test period are shown in appendix C, figures 23 and 24.

31

3.2.4 Damage to Test Article

The test installation sustained substantial damage as shown in figures 14 and 15. The rail element formed an elbow 3.55 m from the end of the rail (Le., nose) and was buckled and severely deformed 0.51 m from the end. The nose assembly was resting to the rear of post 6. The two foundation tubes were moved forward longitudinally less than 5 mm and posts 1 and 2 fractured at ground level. Posts 3 through 7 were fractured near ground level. The blockouts on posts 8 and 9 were twisted and post 10 was split along the longitudinal axis. Tire marks were observed on the top of the blockout at post 10 and along the rail element between post 10 and 11. Posts 11 through 25 were fractured and lying in various places along the installation. The blockouts on posts 26 and 27 were twisted and the rail element pulled off of post 26. Posts 26 through the downstream end anchor were disturbed. The debris pattern extended 47.5 m down from the nose and 3.8 m to the rear of the installation and 14.5 m toward the traffic lanes. Maximum movement of the nose section of the ELT was 7.97 m. The elbow, which formed at 355 mm from the nose, had the maximum dynamic deflection toward traffic lanes of 2.75 m during the test.

3.2.5 Vehicle Damage

Damage to the vehicle is shown in figure 16. Structural damage included deformed left and right frames and sway bar and broken tie rod. Also damaged were the front bumper, hood, grill, radiator, fan, right and left front quarter panels, and right and left front tires. Maximum exterior crush to the vehicle was 380 mm at the center of the bumper at bumper height. No deformation or intrusion of the occupant compartment occurred. The interior of the vehicle is shown in figure 17. Exterior vehicle crush and occupant compartment measurements are shown in appendix B, tables 7 and 8.


A summary of the test results is presented in figure 18. Vehicle angular displacements and accelerations versus time traces are presented in appendix D, figures 29 through 32. The test results were assessed in accordance with the evaluation criteria set forth in NCHRP Report 350 for test 3-31, as described in Chapter IT, Section 2.4.


A. The vehicle was brought to a controlled stop. However, the vehicle overrode and straddled the guardrail and traveled on top of the guardrail until the vehicle came to rest.

32

Figure 14. Vehicle trajectory path after test 473390-2.

33

Figure 15. Installation after test 473390-2.

Figure 16. Vehicle after test 473390-2.

35

Before test

Mtertest

Figure 17. Interior of vehicle for test 473390-2.

36

w General Information Impact Conditions Test Article Deflections (m) -l Test Agency ............. Texas Transportation Institute Speed (km/h) ................ 99.7 Dynamic ................. 7.97

Test No ................. 473390-2 Angle (deg) ................. 0 Permanent ............... 7.60 Date ................... 09/09/98 Exit Conditions Vehicle Damage

Test Article Speed (km/h) ................ Stopped Exterior Type ................... Terminal Angle (deg) ................. NIA VDS .................. 12FC4 Name or Manufacturer ..... Minnesota EL T Occupant Risk Values CDC .................. 12FDEW3 Installation Length (m) ..... 57.1 Impact Velocity (m/s) Maximum Exterior Material or Key Elements ... 1.2 m Flared W-beam Guardrail on x-direction ................ 5.3 Vehicle Crush (mm) ...... 380

Wooden Posts Spaced 1.9 m y-direction •••••••••• I ••••• 1.9 Interior Soil Type and Condition .... Standard Soil, Dry THIV (km/h) ................ 18.9 OCDI . ................ FSOOOOOOO Test Vehicle Ridedown Accelerations (g's) Max. Occ. Com part.

Type ................... Production x-direction ................ -4.0 Deformation (mm) . ...... 0 Designation ............. 2000P y-direction • •••••••• I •••••• -4.6 Post-Impact Behavior Model .................. 1994 Chevrolet 2500 pickup truck PHD (g's) ................... 5.3 (during 1.0 s after impact) Mass (kg) ASI ....................... 0.73 Max. Yaw Angle (deg) . ..... -24

Curb ................. 2084 Max. 0.050-s Average (g's) Max. Pitch Angle (deg) ...... -7 Test Inertial ........... 2000 x-direction . ............... -7.1 Max. Roll Angle (deg) ....... 36 Dummy .............. No dummy y-direction . ............... 3.0 Gross Static ........... 2000 z-direction •••• I ••••••••••• 3.2

Figure 18. Summary of results for test 473390-2, NCHRP Report 350 test 3-31.

The evaluation criteria set forth in NCHRP Report 350 do not take into account the overriding and straddling of the guardrail in an end-on impact. Thus, the ELT is judged to have satisfactorily met the structural adequacy criterion for this test. However, it is important to point out that the vehicle, while proceeding forward on top of the guardrail, has the potential of impacting any hazard shielded by the guardrail that is in the path of the vehicle, e.g., bridge piers, trees, etc. Also, in the case of guardrail approaches to bridges, the vehicle may encounter the bridge rial end or drop off the bridge.

• Occupantltlsk

D. Detached elements, fragments and debris did not penetrate nor show potential for penetrating the occupant compartment. Fractured posts 1 through 7 were strewn in various places covering an area 47.5 m down, 14.5 m toward traffic lanes, and 3.8 m behind the installation. While the debris pattern covered a relatively large area, most of the large pieces of debris were within 3 to 4 m of the guardrail face, which would typically be the shoulder area. Thus, it was judged that the debris did not pose undue hazard to adjacent traffic. No deformation or intrusion into the occupant compartment occurred.


H.II. Data from the accelerometer located at the vehicle center of gravity were digitized for evaluation of occupant risk and were computed as follows. In the longitudinal direction, the occupant impact velocity was 5.3 mls at 0.176 s, the highest 0.010-s occupant ridedown acceleration was -4.0 g's from 0.221 to 0.231 s, and the maximum 0.050-s average acceleration was -7.1 g's between 0.024 and 0.074 s. In the lateral direction, the occupant impact velocity was 1.9 mls at 0.721 s, the highest 0.010-s occupant ridedown acceleration was -4.6 g's from 0.338 to 0.348 s, and the maximum 0.050-s average was 3.0 g's between 0.022 and 0.072 s. The occupant impact velocities are below the preferred limit of 9 mls and the ridedown accelerations are below the preferred limit of 15 g's.

The ELT is judged to have met the occupant risk criteria for this test.


K.IN. The vehicle did not intrude into adjacent traffic lanes nor go behind the guardrail as it came to rest straddling the guardrail.

The ELT is judged to have met the vehicle trajectory criteria for this test.

In summary, this test is judged to have satisfactorily met all evaluation criteria set forth in

38

NCHRP Report 350. However, since the vehicle overrode the guardrail and proceeded on top of the guardrail until the vehicle came to rest astraddle the guardrail, it is important that the guardrail has sufficient ronout lengths to avoid the vehicle impacting any hazard(s), e.g., bridge pier, tree, etc. shielded by the guardrail, or in the case of guardrail approaches to bridges, encountering the bridge rail end or dropping off the bridge.

39

IV. ANALYSIS OF COMPARABLE NCHRP REPORT 230 TESTS

As mentioned previously, the two small car tests required under NCHRP Report 350 are similar to those required under NCHRP Report 230 except for the higher impact speed of 100 km/h versus 96.5 kmIh. Thus, if the two small car tests previously conducted for the ELT under NCHRP Report 230 guidelines are judged to have met all evaluation criteria set forth in NCHRP Report 350, FHW A would consider accepting these tests as equivalent and would not require rerunning of these tests.

The two small car tests previously performed on the ELT by Southwest Research Institute under NCHRP Report 230 guidelines(3) are as follows:

1. Test No. RBCT-13. An 820-kg passenger car impacting the ELT end-on at a nominal impact speed and angle of 96.5 kmIh and 0 degree relative to the tangent section of the guardrail. The left front quarter point of the vehicle is aligned with the centerline of the nose of the terminal. This test is considered to be equivalent to test 3-30 of the NCHRP Report 350 crash test matrix.

2. Test No. RBCT-19. An 820-kg passenger car impacting the ELT at a nominal impact speed and angle of 100 km/h and 15 degrees mid-point between the end of the terminal and the beginning of length-of-need. This test is considered to be equivalent to test 3-34 of the NCHRP Report 350 crash test matrix.

Excerpts of the results for these two tests are provided in this chapter together with an assessment of the test results to determine if the evaluation criteria set forth in NCHRP Report 350 are met or not.

4.1 CRASH TEST RBCT-13 (NCHRP REPORT 350 TEST 3-30)

4.1.1 Test Descriptions

The following are excerpts from the the report, "Test and Evaluation of Eccentric Loader BeT Guardrail Terminals" pertaining to this test. (3)

Test Vehicle: The test vehicle was a 1979 Honda Civic. Gross test weight, including the dummy and instrumentation, was 1986lb (901 kg).

Performance: Impact conditions were 60.5 mph (97.4 km/h) and a 0.2 degree angle. Impact was 14.9 in (37.8 cm) offset to the driver side of the vehicle (centerline of nose of centerline of vehicle). Upon impact, Post 1 fractured and the nose section began to redirect the vehicle behind the rail. At this time a hinge began to form at Post 2 causing the rail to buckle outward as designed. After the vehicle fractured Post 2, the W-beam sprung back into the right

41

side of the vehicle at the door. The vehicle fractured Posts 3 and 4 before coming to rest 75 ft (23 m) downstream and 19ft (5.8 m) behind impact ....

Barrier Damage: The culvert nose piece andfirst three sections of rail were deformed. Posts 1, 2, 3, and 4 were fractured. The nose piece remained attached to the rail during impact.

Vehicle Damage: Damage to the vehicle consisted of sheet metal deformation of both frontfenders, the hood, headlight/grille area, and the right side. Although the right A-pillar and door were moderately deformed into the passenger compartment, no W-beam impingement was noted. The right door window frame was deformed, but the window was not broken. The windshield was cracked from contact with the rear of the hood. The front bumper was displaced rearward at the impact point. Although the rightfront wheel was bent, the tire remained inflated as did the remaining tires.


The results from test no. RBCT -13 were assessed in accordance with the evaluation criteria set forth in NCHRP Report 350 for test 3-30, as described in Chapter IT, Section 2.4.


A. The vehicle gated through the terminal and came to a controlled stop behind the guardrail.

The ELT is judged to have satisfactorily met the structural adequacy criterion for this test.

• Occupant Risk

D. Detached elements, fragments and debris did not penetrate nor show potential for penetrating the occupant compartment. Fractured posts 1 through 4 were strewn in various places, but no information is reported on the debris pattern. There was some deformation or intrusion into the occupant compartment, but the extent of intrusion was not reported. The report noted: "Although the right A-pillar and door were moderately deformed into the passenger compartment, no W-beam impingement was noted. The right door window frame was deformed, but the window was not broken." Also, the report concluded that: "Although there was some intrusion into the right side door, no evidence of spearing or potential spearing was noted. "


H.II. Results of the occupant risk factors computed from the accelerometer data

42

are reported as follows. In the longitudinal direction, the occupant impact velocity was 8.9 mis, the occupant ridedown acceleration was -7.4 g's, and the maximum 0.050-s average acceleration was -14.1 g's. In the lateral direction, the occupant impact velocity was -3.8 mis, the occupant ridedown acceleration was 7.5 g's, and the maximum 0.050-s average was 5.9 g's. The occupant impact velocities are below the preferred limit of 9 mls and the ridedown accelerations are below the preferred limit of 15 g's.

The ELT is judged to have satisfactorily met the occupant risk criteria for this test. There was some deformation and intrusion into the occupant compartment at the right front door area, but the exact extent was unknown and cannot be assessed independently. However, it was judged to have met NCHRP Report 230 requirements.


K.IN. The vehicle did not intrude into adjacent traffic lanes as it gated through the terminal and came to rest behind the guardrail.

The ELT is judged to have satisfactorily met the vehicle trajectory criteria for this test.

In summary, the ELT is judged to have met all evaluation criteria set forth in NCHRP Report 350 for test no 3-30. The actual impact speed of 97.4 kmIh for the test is lower than the nominal impact speed of 100 kmIh, but above the lower tolerance limit of 96 kmIh. As mentioned above, there was some deformation and intrusion into the occupant compartment at the right front door area, but the exact extent was unknown.

4.2 CRASH TEST RBCT-19 (NCHRP REPORT 350 TEST 3-34)

4.2.1 Test Descriptions

The following are excerpts from the the report, "Test and Evaluation of Eccentric Loader BeT Guardrail Terminals" pertaining to this testY)

Test Vehicle: The vehicle used in the test was a 1978 Honda Civic. Gross test weight, including the dummy and instrumentation, was 1905 lb (864 kg) ....

Performance: Impact conditions were 58.9 mph (94.8 km/h) and a 15.0-degree impact angle . ... the vehicle impacted the barrier 1.2 ft (0.5 m) downstream of Post 2. The vehicle remained in contact with the barrier for 12.7 ft (3.0 m) before redirection at a -12.6-degree angle. The vehicle was smoothly redirected although there was some evidence of wheel

43

snagging on Post 3, and the tire disengaged from the rim. The vehicle came to rest 345 it (105 m) downstream and 26ft (8.0 m) behind the impact point.

Barrier Damage: Damage to the barrier consisted of deformation of two sections of Wbeam. Posts 2 through 5 were deflected laterally. The wood blockout on Post 4 was split vertically through the center.

Vehicle Damage: Damage to the vehicle consisted of sheet metal deformation of the left front fender, left side, the hood, and the headlight/grille area. The left front tire was dismounted from the wheel. The front bumper was deformed. The driver window was shattered during impact.


The results from test no. RBCT -19 were assessed in accordance with the evaluation criteria set forth in NCHRP Report 350 for test 3-34, as described in Chapter II, Section 2.4.


A. The terminal contained and redirected the vehicle.

The ELT is judged to have satisfactorily met the structural adequacy criterion for this test.

• Occupant Risk

D. Detached elements, fragments and debris did not penetrate nor show potential for penetrating the occupant compartment. None of the guardrail posts was broken although the left front tire was dismounted from the wheel. No information was reported regarding deformation or intrusion into the occupant compartment. However, review of the sequential photographs and photographs of vehicle damage would indicate that there was no deformation or intrusion into the occupant compartment.


H.II. Results of the occupant risk factors computed from film analysis (longitudinal) and accelerometer data (lateral) are reported as follows. In the longitudinal direction, the occupant impact velocity was 5.2 mis, the occupant ridedown acceleration was -0.7 g's, and the maximum 0.050-s average acceleration was -4.8 g's. In the lateral direction, the occupant impact velocity was 5.9 mis, the occupant ridedown acceleration was-13.7 g's, and the maximum 0.050-s average was 5.9 g's. The occupant impact velocities are below the preferred limit of 9 mls and the ridedown

44

accelerations are below the preferred limit of 15 g's.

The ELT is judged to have met the occupant risk criteria for this test.


K. The vehicle did not intrude into adjacent traffic lanes.

N. The vehicle came to rest 105 m downstream and 8.0 m behind the impact point.

The ELT is judged to have met the vehicle trajectory criteria for this test.

In summary, the ELT is judged to have met all evaluation criteria set forth in NCHRP Report 350 for test no 3-34. The report noted that "All values of Report 230 were met with the exception of the vehicle trajectory requirement of the exit angle not exceeding 60 percent of the impact angle. Although the exit angle at loss of barrier contact exceeded the 60-percent value, the heading angle of the vehicle began to decrease soon after leaving the barrier, and the overall vehicle post impact trajectory is considered to be excellent." However, under NCHRP Report 350 guidelines, the criterion of exit angle not greater than 60 percent of the impact angle is no longer part of evaluation criteria for test no. 3-34.

There are two possible concerns over the equivalency of this test to test 3-34: (1) the actual impact speed of 94.8 kmIh for the test is below the lower tolerance limit of 96 kmIh and (2) the vehicle impacted the barrier 0.5 m downstream of post 2. Both conditions reduced the severity of the impact. However, given the excellent performance of the ELT in this test, i.e., no broken post, maximum dynamic deflection of only 462 mm, relatively low occupant risk factors, and minor damage to the vehicle, it is our opinion that the ELT would have performed satisfactorily at the nominal impact speed of 100 kmIh.

45

v. CONCLUSIONS AND RECOMMENDATIONS

5.1 SUMMARY OF FINDINGS

The Eccentric Loader Terminal (ELT) was successfully crash tested in accordance with NCHRP Report 350 requirements. Note that the ELT design that was successfully crash tested differs from the original design as follows:

• Post 7 is a CRT post instead of a standard line post, and

• The lateral offset for post 2 is 660 mm instead of 635 mm.

According to NCHRP Report 350 requirements, the following five crash tests are considered necessary to qualify a flared terminal like the ELT, including:

• Test 3-30 - small car head-on test,

• Test 3-31 - pickup truck head-on test,

• Test 3-34 - small car redirection test,

• Test 3-35 - pickup truck redirection test, and

• Test 3-39 - pickup truck reverse direction test.

After consultation with FHW A, it was agreed that only two of the five crash tests, the pickup truck head-on and redirection tests (tests 3-31 and 3-35), are required to quality the ELT under NCHRP Report 350 guidelines. FHW A waived the pickup truck reverse direction test (test 3-39) because this test has been shown in previous crash tests to be a non-discriminating test for flared terminals. The two small car tests (tests 3-30 and 3-34) were successfully performed under NCHRP Report 230 guidelines. FHW A may waive the requirements for these two tests if these tests are shown to have satisfactorily met the evaluation criteria set forth under NCHRP Report 350.

Brief summary descriptions of the two crash tests conducted under this study are presented as follows:

• Test no. 473390-1 (NCHRP Report 350 test 3-35) - pickup truck redirection test. The ELT contained and redirected the vehicle. The vehicle did not penetrate, underride, or override the installation. Detached elements, fragments or debris did not penetrate nor show potential to penetrate the occupant compartment. The fractured posts 4 through 7 were strewn in various places covering an area 26.6 m down from the point of impact and 25.9 m behind the rail. Maximum deformation

47

of the occupant compartment was 33 mm (36 percent reduction of space) in the front, but since the location is in the front center floor pan area, it was judged not to cause any serious injury. The vehicle remained upright during and after the collision period. The vehicle did not intrude into adjacent traffic lanes as it came to rest adjacent the rail. Longitudinal occupant impact velocity was 7.3 mls and longitudinal occupant ridedown acceleration was -9.7 g's. Exit angle at loss of contact was 18.8 degrees which was 90 percent of the impact angle. However, the vehicle yawed toward the installation after loss of contact.

A summary of the performance evaluation for this test is shown in table 1. This test is judged to have satisfactorily met all evaluation criteria set forth in NCHRP Report 350. However, the test is considered a marginal pass since the W-beam rail element was almost half tom at the second splice and over three-quarters tom at the third splice.

• Test no. 473390-2 (NCHRP Report 350 test 3-31) - pickup truck head-on test. The vehicle overrode and straddled the guardrail and traveled on top of the guardrail until the vehicle came to a controlled stop. Detached elements, fragments and debris did not penetrate nor show potential for penetrating the occupant compartment. Fractured posts 1 through 7 were strewn in various places covering an area 47.5 m down, 14.5 m toward traffic lanes, and 3.8 m behind the installation. No deformation or intrusion into the occupant compartment occurred. The vehicle remained upright during and after the collision period. Occupant risk factors were within the limits specified in NCHRP Report 350. The vehicle did not intrude into adjacent traffic lanes and came to rest astraddle the installation.

A summary of the performance evaluation for this test is shown in table 2. This test is judged to have satisfactorily met all evaluation criteria set forth in NCHRP Report 350. However, since the vehicle overrode the guardrail and proceeded on top of the guardrail until the vehicle came to rest astraddle the guardrail, it is important that the guardrail has sufficient runout length to minimize the potential for the vehicle to impact the hazard(s), e.g., bridge pier, tree, etc., shielded by the guardrail, or to impact the bridge rail end or drop off the bridge in case of a guardrail approach to a bridge.

The two small car tests previously performed under NCHRP Report 230 guidelines were evaluated to determine if these tests have satisfactorily met the evaluation criteria set forth under NCHRP Report 350. Brief summary descriptions of these two crash tests are presented as follows:

• Test no. RBCT -13 (NCHRP Report 350 test 3-30) - small car head-on test. The vehicle gated through the terminal and came to a controlled stop behind the guardrail. Detached elements, fragments and debris did not penetrate nor show potential for penetrating the occupant compartment. Fractured posts 1 through 4

48

Table 1. Performance evaluation summary for test 473390-1, NCHRP Report 350 test 3-35.

Test Agency: Texas Transportation Institute Test No.: 473390-1 Test Date: 09/07/98

I NCHRP Report 350 Evaluation Criteria I Test Results I Assessment I Structural Adequacy

A. Test article should contain and redirect the vehicle; the The ELT contained and redirected the vehicle. vehicle should not penetrate, underride, or override the However, the rail element had a 180 mm long tear at installation although controlled lateral deflection of the test the second splice and a 270 mm long tear at the third Pass article is acceptable. splice. The vehicle did not penetrate, underride, or

override the installation.

Occupant Risk

D. Detached elements, fragments or other debris from the test Detached elements, fragments or debris did not article should not penetrate or show potential for penetrate nor show potential to penetrate the occupant penetrating the occupant compartment, or present an undue compartment. The fractured posts 4 through 7 were hazard to other traffic, pedestrians, or personnel in a work strewn in various places covering an area 26.6 m down zone. Deformations of, or intrusions into, the occupant from the point of impact and 25.9 m behind the rail. Pass compartment that could cause serious injuries should not be Maximum deformation of the occupant compartment permitted. was 33 mm (36 percent reduction of space), but since

the location is in the front center floor pan area, it was judged not to cause any serious injury.

F. The vehicle should remain upright during and after collision The vehicle remained upright during and after the Pass

although moderate roll, pitching and yawing are acceptable. collision period.

Vehicle Trajectory

K. After collision, it is preferable that the vehicle's trajectory The vehicle did not intrude into adjacent traffic lanes as Pass*

not intrude into adjacent traffic lanes. it came to rest adjacent the rail.

L. The occupant impact velocity in the longitudinal direction Longitudinal occupant impact velocity was 7.3 mls and should not exceed 12 mls and the occupant ridedown longitudinal occupant ridedown acceleration was

Pass acceleration in the longitudinal direction should not exceed -9.7 g's. 20g's.

M. The exit angle from the test article preferably should be less Exit angle at loss of contact was 18.8 degrees which than 60 percent of test impact angle, measured at time of was more than 60 percent of the impact angle.

Fail * vehicle loss of contact with test device. However, the vehicle yawed toward the installation

after loss of contact.

*Criterion K and M are preferable, not required.

Ul o

Table 2. Performance evaluation summary for test 473390-2, NCHRP Report 350 test 3-31.

Test Agency: Texas Transportation Institute Test No.: 473390-2 Test Date: 09/09/98

NCHRP Report 350 Evaluation Criteria Test Results Assessment

Structural Adeguacy

C. Acceptable test article performance may be by redirection, The vehicle overrode and straddled the guardrail and controlled penetration, or controlled stopping of the vehicle. traveled on top of the guardrail until the vehicle Pass

came to a controlled stop.

Occupant Risk

D. Detached elements, fragments or other debris from the test Detached elements, fragments and debris did not article should not penetrate or show potential for penetrating penetrate nor show potential for penetrating the the occupant compartment, or present an undue hazard to other occupant compartment. Fractured posts 1 through 7 traffic, pedestrians, or personnel in a work zone. Deformations were strewn in various places covering an area Pass of, or intrusions into, the occupant compartment that could 47.5 m down, 14.5 m toward traffic lanes, and 3.8 m cause serious injuries should not be permitted. behind the installation. No deformation or intrusion

into the occu_pant compartment occurred.



H. Occupant impact velocities should satisfy the following:

Occupant Velocity Limits (mls) Longitudinal occupant impact velocity = 5.3 mls Pass

Component Preferred Maximum Lateral occupant impact velocity = 1.9 mls

Longitudinal and lateral 9 12

I. Occupant ridedown accelerations should satisfy the following:

Occupant Ridedown Acceleration Limits (g's) Longitudinal ridedown acceleration = -4.0 g's Pass

Component Preferred Maximum Lateral ridedown acceleration = -4.6 g's


Vehicle Trajectory

K. After collision, it is preferable that the vehicle's trajectory not The vehicle did not intrude into adjacent traffic Pass*

intrude into adjacent traffic lanes. lanes.

N. Vehicle traiectory behind the test article is acceptable. The vehicle came to rest astraddle the installation. N/A

*Criterion K is preferable. not required.

were strewn in various places, but no information is reported on the debris pattern. There was some deformation or intrusion into the occupant compartment, but the extent of intrusion was not reported. The vehicle remained upright during and after the collision period. The occupant impact velocities were 8.9 mls (longitudinal) and -3.8 mls (lateral). The occupant ridedown accelerations were -7.4 g's (longitudinal) and 7.5 g's (lateral). The vehicle did not intrude into adjacent traffic lanes as it gated through the terminal and came to rest behind the guardrail.

A summary of the performance evaluation for this test is shown in table 3. This test is judged to have satisfactorily met all evaluation criteria set forth in NCHRP Report 350. The actual impact speed of 97.4 kmIh for the test is lower than the nominal impact speed of 100 kmIh, but above the lower tolerance limit of 96 kmIh.

• Test no. RBCT-19 (NCHRP Report 350 test 3-34) - small car redirection test. The terminal contained and redirected the vehicle. Detached elements, fragments and debris did not penetrate nor show potential for penetrating the occupant compartment. There is no indication of any deformation or intrusion into the occupant compartment. The vehicle remained upright during and after the collision period. The occupant impact velocities were 5.2 mls (longitudinal) and 5.9 mls (lateral). The occupant ridedown accelerations were -0.7 g's (longitudinal) and -13.7 g's (lateral). The vehicle did not intrude into adjacent traffic lanes, coming to rest 105 m downstream and 8.0 m behind the impact point.

A summary of the performance evaluation for this test is shown in table 4. This test is judged to have satisfactorily met all evaluation criteria set forth in NCHRP Report 350. The impact speed of 94.8 kmIh for the test is below the lower tolerance limit of 96 kmIh. However, given the excellent performance of the ELT in this test, it is our opinion that the ELT would have performed satisfactorily at the nominal impact speed of 100 kmIh.

5.2 CONCLUSIONS AND RECOMMENDATIONS

The Eccentric Loader Terminal (ELT), with two minor design modification (replacing the standard line post at post 7 with a CRT post and using a lateral offset of 660 mm at post 2 instead of 635 mm), is judged to have successfully met all requirements and evaluation criteria set forth in NCHRP Report 350. It is, therefore, recommended that the ELT be approved as a NCHRP Report 350 terminal.

However, since the vehicle overrode the guardrail and proceeded on top of the guardrail until the vehicle came to rest astraddle the guardrail in the pickup truck head-on test (test 3-35), it

51

is recommended that the ELT terminal be used with guardrails that have sufficient ronout lengths to minimize the potential for the vehicle to impact the hazard(s), e.g., bridge pier, tree, etc., shielded by the guardrail.

52

Table 3. Performance evaluation summary for test RBCT -13, NCHRP Report 350 test 3-30.

Test Agency: Southwest Research Institute Test No.: RBCT -13 Test Date: xx/xx/xx

I NCHRP Report 350 Evaluation Criteria I Test Results I Assessment I Structural Adeguacy

C. Acceptable test article performance may be by redirection, The vehicle gated through the terminal and came to Pass

controlled penetration, or controlled stopping of the vehicle. a controlled stop behind the guardrail.

Occupant Risk

D. Detached elements, fragments or other debris from the test Detached elements, fragments and debris did not article should not penetrate or show potential for penetrating penetrate nor show potential for penetrating the the occupant compartment, or present an undue hazard to other occupant compartment. Fractured posts 1 through 4 traffic, pedestrians, or personnel in a work zone. Deformations were strewn in various places, but the debris pattern

Pass of, or intrusions into, the occupant compartment that could was not reported. There was some deformation or cause serious injuries should not be permitted. intrusion into the occupant compartment, but the

extent was also not reported. This test was judged to have met this criterion under NCHRP Report 230.




Occupant Velocity Limits (mls) Longitudinal occupant impact velocity = 8.9 mls Lateral occupant impact velocity = -3.8 mls Pass

Component Preferred Maximum



Occupant Ridedown Acceleration Limits (g's) Longitudinal occupant impact velocity = -7.4 mls Lateral occupant impact velocity = 7.5 mls Pass

Component Preferred Maximum


Vehicle Trajectory

K. After collision, it is preferable that the vehicle's trajectory not The vehicle did not intrude into adjacent traffic Pass intrude into adjacent traffic lanes. lanes.

N. Vehicle traiectory behind the test article is acceptable. The vehicle came to rest behind the jUlardrail. Pass

*Criterion K is preferable, not required.

Table 4. Performance evaluation summary for test RBCT-19, NCHRP Report 350 test 3-34.

Test Agency: Southwest Research Institute Test No.: RBCT-19 Test Date: 12/19/84

NCHRP Report 350 Evaluation Criteria Test Results Assessment

Structural Adeguac~

C. Acceptable test article performance may be by redirection, The terminal contained and redirected the vehicle. Pass controlled penetration, or controlled stopping of the vehicle.

Occupant Risk

D. Detached elements, fragments or other debris from the test Detached elements, fragments and debris did not article should not penetrate or show potential for penetrating penetrate nor show potential for penetrating the the occupant compartment, or present an undue hazard to other occupant compartment. No indication that there was

Pass traffic, pedestrians, or personnel in a work zone. Deformations any deformation or intrusion into the occupant of, or intrusions into, the occupant compartment that could compartment. cause serious injuries should not be permitted.

F. The vehicle should remain upright during and after collision The vehicle remained upright during and after the Pass although moderate roll, pitching and yawing are acceptable. collision period.


Occupant Velocity Limits (m/s) Longitudinal occupant impact velocity = 5.2 mls Pass

Component Preferred Maximum Lateral occupant impact velocity = 5.9 mls



Occupant Ridedown Acceleration Limits (g's) Longitudinal ridedown acceleration = -0.7 g's Pass

Component Preferred Maximum Lateral ridedown acceleration = -13.7 g's


Vehicle TrajectorY

K. After collision, it is preferable that the vehicle's trajectory not The vehicle did not intrude into adjacent traffic Pass

intrude into adjacent traffic lanes. lanes.

N. Vehicle trajectory behind the test article is acceptable. Vehicle came to rest 8.0 m behind the guardrail. Pass

*Criterion K is preferable, not required.

APPENDIX A. CRASH TEST PROCEDURES AND DATA ANALYSIS

The crash test and data analysis procedures were in accordance with guidelines presented in NCHRP Report 350. Brief descriptions of these procedures are presented as follows.

ELECTRONIC INSTRUMENTATION AND DATA PROCESSING

The test vehicle was instrumented with three solid-state angular rate transducers to measure roll, pitch and yaw rates; a triaxial accelerometer near the vehicle center-of-gravity to measure longitudinal, lateral, and vertical acceleration levels, and a back-up biaxial accelerometer in the rear of the vehicle to measure longitudinal and lateral acceleration levels. These accelerometers were ENDEVCO Model 2262CA, piezoresistive accelerometers with a ±100 grange.

The accelerometers are strain gage type with a linear millivolt output proportional to acceleration. Rate of tum transducers are solid state, gas flow units designed for high g service. Signal conditioners and amplifiers in the test vehicle increase the low level signals to a ±2.5 Volt maximum level. The signal conditioners also provides the capability of a R-Cal or shunt calibration for the accelerometers and a precision voltage calibration for the rate transducers. The electronic signals from the accelerometers and rate transducers are transmitted to a base station by means of a 15 channel, constant bandwidth, Inter-Range Instrumentation Group (IRIG), FMIFM telemetry link for recording on magnetic tape and for display on a real-time strip chart. Calibration signals, from the test vehicle, are recorded minutes before the test and also immediately afterwards. A crystal controlled time reference signal is simultaneously recorded with the data. Pressure sensitive switches on the bumper of the impacting vehicle are actuated just prior to impact by wooden dowels to indicate the elapsed time over a known distance to provide a measurement of impact velocity. The initial contact also produces an "event" mark on the data record to establish the exact instant of contact with the installation.

The multiplex of data channels, transmitted on one radio frequency, is received at the data acquisition station, and demultiplexed onto separate tracks of a 28 track, (IRIG.) tape recorder. After the test, the data are played back from the tape machine, filtered with SAE 1211 filters, and digitized using a microcomputer, at 2000 samples per second per channel, for analysis and evaluation of impact performance.

All accelerometers are calibrated annually (SAE 1211 4.6.1) by means of a Endevco 2901, precision primary vibration standard. This device along with its support instruments is returned to the factory annually for a National Institute of Standards Technology (NIST) traceable calibration. The subsystems of each data channel are also evaluated annually, using instruments with current NIST traceability, and the results factored into the accuracy of the total data channel, per SAE 1211. Calibrations and evaluations will be made at any time a data channel is suspected of any anomalies.

55

ANTHROPOMORPHIC DUMMY INSTRUMENTATION

An Alderson Research Laboratories Hybrid II, 50th percentile male anthropomorphic dummy, restrained with lap and shoulder belts, was placed in the driver's position of the 820C vehicle. The dummy was un-instrumented. Use of a dummy in the 2000P vehicle is optional according to NCHRP Report 350 and there was no dummy used in the tests with the 2000P vehicle.

PHOTOGRAPHIC INSTRUMENTATION AND DATA PROCESSING

Photographic coverage of the test included three high-speed cameras: one overhead with a field of view perpendicular to the ground and directly over the impact point; one placed behind the installation at an angle; and a third placed to have a field of view parallel to and aligned with the installation at the downstream end. A flash bulb activated by pressure sensitive tape switches was positioned on the impacting vehicle to indicate the instant of contact with the installation and was visible from each camera. The films from these high-speed cameras were analyzed on a computer-linked Motion Analyzer to observe phenomena occurring during the collision and to obtain time-event, displacement and angular data. A BetaCam, a VHS-format video camera and recorder, and still cameras were used to record and document conditions of the test vehicle and installation before and after the test.

TEST VEHICLE PROPULSION AND GUIDANCE

The test vehicle was towed into the test installation using a steel cable guidance and reverse tow system. A steel cable for guiding the test vehicle was tensioned along the path, anchored at each end, and threaded through an attachment to the front wheel of the test vehicle. An additional steel cable was connected to the test vehicle, passed around a pulley near the impact point, through a pulley on the tow vehicle, and then anchored to the ground such that the tow vehicle moved away from the test site. A 2 to 1 speed ratio between the test and tow vehicle existed with this system. Just prior to impact with the installation, the test vehicle was released to be free-wheeling and unrestrained. The vehicle remained free-wheeling, i.e., no steering or braking inputs, until the vehicle cleared the immediate area of the test site, at which time brakes on the vehicle were activated to bring it to a safe and controlled stop, if needed.

56

APPENDIX B. TEST VEHICLE PROPERTIES AND INFORMATION

DATE: -----'--9_-_7_-_9_8 ___ _ TEST NO.: ----..:4'--'-7---==3::....:3::....:9=-:°=----'-1 ___ _ VIN NO.: _1:.-.:G::...:C::...:G::...:C=2~4_'_'K_'_'0=R--'-'E"--1'-'3::...:2=_::8::...:2=_1'_____ __ _

YEAR: ~1.,::::.9..::.9---,-4 ____ _ MAKE: _---'C::.....cH--=-E==-V-----'--Y _____ _ MODEL: --=2.=5-=0-=0'--'-p-J.I'-U-"'------_______ _

TIRE INFLATION PRESSURE: ____ _ ODOMETER: _-'1_4'-1'-..:2=-3_6 ____ _ TIRE slzE:~L::.cT~2"__4_'__'5~7'_5:::::..:...:..R_'_1 .,::::.6_

MASS DISTRIBUTION (kg) LF _--=5'---'50...=2=--__ RF_-----"'5C-'-7-=2=--__

DESCRIBE ANY DAMAGE TO VEHICLE PRIOR TO TEST:

TEST INERTIAL C.M.

GEOMETRY - (mm)

A 1860 E 1290 1020

780 F 5420 640 0

C 3350 G 1467.3 65 P 1840 M 425 Q

TEST MASS - (kg) CURB INERTIAL

Ml 1186 1124

M2 885 876

MT 2071 2000

LR __ 4_4"--4'-----_ RR_-----.:.4=3=2 __

<£. VEHICLE

1610 1615

740

440

o WHEEL TRACK

• Denotes accelerometer location.

NOTES: ____ _

ENGINE TYPE: 8 CYL. ENGINE CID: 5.7 L

TRANSMISSION TYPE:

X AUTO _ MANUAL

OPTIONAL EQUIPMENT:

DUMMY DATA: TYPE: ______ _ MASS: ______ _

SEAT POSITION: ____ _

725 905

1500

4070

GROSS STATIC

Figure 19. Vehicle properties for test 473390-1.

57

Table 5. Exterior crush measurements for test 473390-1.

VEHICLE CRUSH MEASUREMENT SHEET!

Complete When Applicable

End Damage Side Damage

Undeformed end width Bowing: BI -- Xl --Comer shift: A I B2 X2 -- --

A2 -

End shift at frame (CDC) Bowing constant (check one) Xl + X2 =

< 4 inches 2 --> 4 inches

Note: Measure CI to C6 from Driver to Passenger side in Front or Rear impactsRear to Front in Side impacts.

Direct Damage Specific

C1 C2 C3 C4 Impact Plane* of Width ** Max*** Field Number C-Measurements (CDC) Crush L**

Cs

1 Top of front bumper 700 -440 1600 +100 +20 -70 -120 -210

C6 ±D

-440 0

2 820 mm above ground 700 -390 1900 0 -40 -50 -60 -40 -390 +1090

ITable taken from National Accident Sampling System (NASS).

*Identify the plane at which the C-measurements are taken (e.g., at bumper, above bumper, at sill, above sill, at beltline, etc.) or label adjustments (e.g., free space).

Free space value is defined as the distance between the baseline and the original body contour taken at the individual C locations. This may include the following: bumper lead, bumper taper, side protrusion, side taper, etc. Record the value for each C-measurement and maximum crush.

**Measure and document on the vehicle diagram the beginning or end of the direct damage width and field L (e.g., side damage with respect to undamaged axle).

***Measure and document on the vehicle diagram the location of the maximum crush. Note: Use as many lines/columns as necessary to describe each damage profile.

58

Table 6. Occupant compartment measurements for test 473390-1.

Occupant Compartment Deformation

59

A1

A2

A3

81

82

B3

C1

C2

C3

01

02

03

E1

E2

F

G

H

BEFORE

1040

1090

1044

1079

1012

1080

1376

1243

1370

315

93

312

1596

1595

1475

1475

1100

1100

AFTER

1040

1090

1044

1075

950

1070

1376

1243

1370

315

60

305

1591

1600

1470

1475

1595

1100

DATE: -.::::.9_--'9::.-.----=:9--=8'--__ _ TEST NO.: 473390-2 VIN No.:_1 G_C_G_C_2_4_K_9--'.R_E"--2_7_5c-3=-.6.::....3-=---__ _

YEAR: -----'--1-=-9-=9_4'-----___ _ MAKE: _---.:C~H__=E:..::V-cY'--_____ _ MODEL: -=2=5-=0-=0'----'p-/I'---=-U ________ _

TIRE INFLATION PRESSURE: _____ _ ODOMETER: __ 1.:.-6=2--=6-=2"-'6"--____ _ TI RE SIZE:--....eL==..T'---'2=.4-=-=5--'-7-=5:..:.R.:.-1:.....:6"'--_

MASS DISTRIBUTION (kg) LF _.....:5::0...7"---,-1 __ _ RF_~5"-4_'__"'.9 __ _

DESCRIBE ANY DAMAGE TO VEHICLE PRIOR TO TEST:

GEOMETRY - (mm)

A 1860 1340 1050 N

B 760 K 635 0

C 3345 G 1471.8 75

D 1800 H M 425 Q

TEST MASS - (kg) CURB INERTIAL

M1 1156 1120

M2 928 880

MT 2084 2000

LR __ 4-,-,2=.2=-__ RR __ 4:....::5:....:8=---__

If. VEHICLE

1600

1620

755

445

o WHEEL TRACK

R

S

T

U

• Denotes accelerometer location.

NOTES: R-100mm TOLT

ENGINE TYPE:--=8--..:C=-Y..:....=L::...... __ ENGINE CID: _5:c...:.:. 7'------=L'-----__

TRANSMISSION TYPE:

X AUTO _ MANUAL

OPTIONAL EQUIPMENT:

8 LUGS

DUMMY DATA:

TYPE: _______ _

MASS: _______ _ SEAT POSITION: _____ _

710

920

1500

4085

GROSS STATIC

Figure 20. Vehicle properties for test 473390-2.

60

Table 7. Exterior crush measurements for test 473390-2.

VEHICLE CRUSH MEASUREMENT SHEETl

Complete When Applicable

End Damage Side Damage

Undeformed end width Bowing: BI -- Xl --Comer shift: A I B2 X2 -- --

A2

End shift at frame (CDC) Bowing constant (check one) Xl + X2 =

< 4 inches 2 --> 4 inches

Note: Measure C I to C6 from Driver to Passenger side in Front or Rear impactsRear to Front in Side impacts.

Direct Damage Specific

C1 C2 C3 C4 Impact Plane* of Width ** Max*** Field Number C-Measurements (CDC) Crush L**

Cs

1 Center of f front bumper 770 380 1640 320 310 380 320 210

ITable taken from National Accident Sampling System (NASS).

C6 ±D

140

*Identify the plane at which the C-measurements are taken (e.g., at bumper, above bumper, at sill, above sill, at beltline, etc.) or label adjustments (e.g., free space).

0

Free space value is defined as the distance between the baseline and the original body contour taken at the individual C locations. This may include the following: bumper lead, bumper taper, side protrusion, side taper, etc. Record the value for each C-measurement and maximum crush.

**Measure and document on the vehicle diagram the beginning or end of the direct damage width and field L (e.g., side damage with respect to undamaged axle).

***Measure and document on the vehicle diagram the location of the maximum crush. Note: Use as many lines/columns as necessary to describe each damage profile.

61

Table 8. Occupant compartment measurements for test 473390-2.

Tru~k

Occupant Compartment Deformation

62

A1

A2

A3

B1

B2

B3

C1

C2

C3

01

02

03

E1

E2

F

G

H

BEFORE

1060

1090

1050

1084

1065

1072

1380

1258

1372

305

153

304

1595

1592

1475

1475

900

900

AFTER

1060

1090

1050

1084

1065

1072

1380

1258

1372

305

153

304

1595

1592

1475

1475

900

900

APPENDIX C. SEQUENTIAL PHOTOGRAPHS

0.000 s

0.049 s

0.122 s

0.219 s

Figure 21. Sequential photographs for test 473390-1 (overhead and frontal views).

63

0.341s

0.487 s

0.658 s

0.926 s

Figure 21. Sequential photographs for test 473390-1 (overhead and frontal views ) (continued).

64

0.000 s 0.341 s

0.487 s

0.122 s 0.658 s

0.341 s 0.926 s

Figure 22. Sequential photographs for test 473390-1 (oblique view).

65

0.000 s

0.049 s

0.148 s

0.246 s

Figure 23. Sequential photographs for test 473390-2 (overhead and frontal views).

66

0.344 s

0.492 s

0.639 s

0.787 s

Figure 23. Sequential photographs for test 473390-2 (overhead and frontal views ) (continued).

67

0.000 s

0.049 s

0.148 s

0.246 s

Figure 24. Sequential photographs for test 473390-2 (oblique views).

68

0.344 s

0.492 s

0.639 s

0.787 s

Figure 24. Sequential photographs for test 473390-2 (oblique views ) (continued).

69

APPENDIX D. VEHICLE ANGULAR DISPLACEMENTS AND ACCELERATIONS

71

~ tv

5

0

-5

-10

Crash Test 473390-1 Vehicle Mounted Rate Transducers

Pitch

+-=,:::;e~-==:..-.--t----.;;;~:--+-----t----I---++-----+----+----;;t'~F---~ Roll

_____ , _______ , - - - - - - .!. - - - - - - ,_ - - - - - _, - - - - - - 1- ___________ _

Axes are vehicle-fixed. Sequence for determining orientation is:

m -15 1. Yaw CD 'tJ 2. Pitch -- -20 c:

I I I I I I I I I

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -I I I I I , I I I

3. Roll CD E CD u -25 as

I I I I I I I I

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -I I I I I I I I

a. en is -30 - - - - - - I - - - - - - -, - - - - - - ,- - - - - - - I - - - - - - ~ - - - - - - 1- - - - - - -. - - - - - - ,- - - - - - - I - - - - - -

Yaw

-35 - - - - - - - - - - - - - - - - - - - - - - - - - - - -I J I I

-40

-45 - - - - - -,- - - - - - -, - - - - - -,- - - - - - -,- - - - - -, - - - - - -,-~---....-

-50~---------------------------------------------------------------------~

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Time after impact (s)

Figure 25. Vehicular angular displacements for test 473390-1.

30

25

- 20 U) -0)

15 -c 0 10 +i as .. CD 5 'ii u

0 u as fti -5 c

--J :g W = -10 -"0,

-15 c 0 .J -20

-25

-30 0.0

I 60 Hz Filter I

0.1 0.2 0.3

Crash Test 473390-1 Accelerometer at center of gravity

0.4 0.5 0.6


Test Article: Minnesota EL T Test Vehicle: 1994 Chevrolet 2500 pickup truck Test Inertial Weight: 2000 kg Gross Static Weight: 2000 kg Impact Speed: 102.1 km/h Impact Angle: 21.0 degrees at beginning of LON

0.7 0.8 0.9

Figure 26. Vehicle longitudinal accelerometer trace for test 473390-1 (accelerometer located at center of gravity).

1.0

30

25

20 - 15 en b -c 10 0 .. 5 '" ... G)

0 "ii u u -5 '" ......,J 'is

-10 ..f:::>. ... S '" -15 ..J

-20

-25

-30 0.0

I 60 Hz Filter I Crash Test 473390-1 Accelerometer at center of gravity

_________________________________________ r-------J.----..J....----..L.----, Test Article: Minnesota EL T Test Vehicle: 1994 Chevrolet 2500 pickup truck Test Inertial Weight: 2000 kg Gross Static Weight: 2000 kg Impact Speed: 102.1 km/h Impact Angle: 21.0 degrees at beginning of

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

0.1 0.2 0.3 0.4 0.5 0.6 0.7


Figure 27. Vehicle lateral accelerometer trace for test 473390-1 (accelerometer located at center of gravity).

0.8 0.9 1.0

I 60 Hz Filter I 30

25

20 - 15 a, -c 10 0

i 5 ~

CD 'i) 0 u u as -5 ca 'l u -10 Ul t= CD > -15

-20

-25

-30 0.0 0.1 0.2 0.3


0.4 0.5 0.6

Time after impact (5)

Test Article: Minnesota EL T Test Vehicle: 1994 Chevrolet 2500 pickup truck Test Inertial Weight: 2000 kg Gross Static Weight: 2000 kg Impact Speed: 102.1 km/h Impact Angle: 21.0 degrees at beginning of

0.7 0.8 0.9

Figure 28. Vehicle vertical accelerometer trace for test 473390-1 (accelerometer located at center of gravity).

1.0

Crash Test 473390-2 Vehicle Mounted Rate Transducers

40.-------------------------------------------------------------------------~

30 , , , - - - - - - - - - - - - - - - - - - - -

I I I I I I - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

20 - - - - - -,- - - - - - -, - - - - - - ,- - - - - - -, - - - - - - T -

, , , - - - - - - - - - - - - - - - - - - - - - - -

-10

, ,

-20 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -I I I I I I I I

-30~------------------------------------------------------------------------~

Roll

Axes are vehicle-fixed. Sequence for determining orientation is:

1. Yaw 2. Pitch 3. Roll

Pitch

Yaw

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0


Figure 29. Vehicular angular displacements for test 473390-2.

I 60 Hz Filter I

15 -en '"en - 10 c: 0 += ca .. 5 CD a; () () ca 0

'ii c:

'-l =c '-l ~

-5 .... "0, c: -10 0 ..J

-15

-20

0.0 0.1 0.2 0.3


Test Article: Minnesota EL T Test Vehicle: 1994 Chevrolet 2500 pickup truck Test Inertial Weight: 2000 kg

- - - - - - - - - Gross Static Weight: 2000 kg Impact Speed: 99.7 km/h Impact Angle: 0 degrees on nose

0.4 0.5 0.6 0.7 0.8 0.9


Figure 30. Vehicle longitudinal accelerometer trace for test 473390-2 (accelerometer located at center of gravity).

1.0

I 60 Hz Filter I 20

15

- 10 U) -Q -C 0 5 +:i as .. G)

0 'ii Co) Co) as

.....,J 'i -5 00 ..

G) -as -10 ..I

-15

0.0 0.1


Test Article: Minnesota EL T - - - - - - - - - - Test Vehicle: 1994 Chevrolet 2500 pickup truck

0.2 0.3 0.4

Test Inertial Weight: 2000 kg _ _ _ _ _ _ _ _ _ _ Gross Static Weight: 2000 kg

Impact Speed: 99.7 km/h Impact Angle: 0 degrees on nose

0.5 0.6 0.7 0.8


Figure 31. Vehicle lateral accelerometer trace for test 473390-2 (accelerometer located at center of gravity).

0.9 1.0

I 60 Hz Filter I

15

- 10 m -c 0

5 i ... Q)

a; 0 u u ca

-J Ci -5 u \0 t:

Q)

> -10

-15

-20

0.0 0.1 0.2 0.3


0.4 0.5 0.6


Test Article: Minnesota EL T Test Vehicle: 1994 Chevrolet 2500 pickup truck Test Inertial Weight: 2000 kg Gross Static Weight: 2000 kg Impact Speed: 99.7 km/h Impact Angle: 0 degrees on nose

0.7 0.8 0.9

Figure 32. Vehicle vertical accelerometer trace for test 473390-2 (accelerometer located at center of gravity).

1.0

REFERENCES

1. Ross, H. E., Jr., D. L. Sicking, R. A. Zimmer and J. D. Michie, Recommended Procedures for the Safety Performance Evaluation of Highway Features, National Cooperative Highway Research Program Report 350, Transportation Research Board, National Research Council, Washington, D.C., 1993.

2. Michie, J. D., Recommended Proceduresfor the Safety Performance Evaluation of Highway Appurtenances, National Cooperative Highway Research Program Report 230, Transportation Research Board, National Research Council, Washington, D.C., March 1981.

3. Bronstad, M. E., J. B. Mayer, Jr., J. H. Hatton, Jr., L. C. Meczkowski, Test and Evaluation of Eccentric Loader BeT Guardrail Terminals Volume I - Research Report and Volume IT - Appendix, Report FHW AJRD-86/009 and FHW A/RD-86/01 0, Southwest Research Institute, San Antonio, Texas, September 1985.

4. W-Beam Guardrail End Treatments, FHW A Technical Advisory T5040.25, January 7, 1986.

81

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Crash Testing and Evaluation of the Eccentric Loader Terminal (ELT) · 2017. 1. 4. · evaluation criteria. The ELT, with two minor design modifications (replacing the standard line