ROBUST PROJECT CIDAUT WP5 - Computational Mechanics …€¦ · · 2006-05-22ROBUST PROJECT CIDAUT WP5 - Computational Mechanics B1 Barrier – Steel N2 MAIN REPORT ... 3.3.3 Analysis

ROBUST PROJECT

CIDAUT WP5 - Computational Mechanics B1 Barrier – Steel N2 MAIN REPORT Volume 1 of 1

November 2005 Doc. No.: ROBUST-5-015 – Rev 0

Main Report

286-2-1-no-en

Report title:

WP5 - Computational Mechanics B5 Concrete Barrier

Client:

CIDAUT

Doc. no.:

ROBUST-5-015

Project no.:

202.813023 / ROBUST-GRD1-2002-70021

Reporter(s):

J García

Abstract:

The Robust Project aims to improve scientific and technical knowledge on the main issues still open in the new European standards on the road restraint system EN1317. The knowledge acquired will form the basis of updated standards for EN 1317 and lead to more advanced road restraint systems and improve road-users safety. This report is part of the deliverables from Work Package 5 – Computational Mechanics. This report documents the simulations performed on the B2 steel barrier. The simulations were performed by CIDAUT.

Keywords:

Restricted

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Free distribution

Ref. allowed

Rev. no. Date Prepared by Checked by Approved by Reason for revision

0 22/5/6 J Garcia Public release

ROBUST project Page i

CIDAUT ROBUST-5-015 – Rev 0

WP5 - Computational Mechanics B1 Steel Barrier MAIN REPORT

CONTENTS

1 INTRODUCTION..................................................................................................1

2 SUMMARY AND CONCLUSIONS .......................................................................2 2.1 Summary..............................................................................................................2 2.2 Conclusions .........................................................................................................2

3 BARRIER – B1 VS GEOMETRO. FULL LENGTH................................................3 3.1 General ................................................................................................................3 3.2 Additional data .....................................................................................................3 3.3 Input data.............................................................................................................4 3.3.1 Test item ..............................................................................................................4 3.3.2 Test procedure.....................................................................................................4 3.3.3 Analysis data........................................................................................................4 3.4 Analysis results ....................................................................................................7

4 BARRIER – B1 VS GEOMETRO. REDUCED LENGTH.....................................14 4.1 General ..............................................................................................................14 4.2 Additional data ...................................................................................................14 4.3 Input data...........................................................................................................14 4.3.1 Test item ............................................................................................................14 4.3.2 Test procedure...................................................................................................15 4.3.3 Analysis data......................................................................................................15 4.4 Analysis results ..................................................................................................18

5 BARRIER – B1. REDUCED MODELS (SIGMA POSTS)....................................25 5.1 General ..............................................................................................................25 5.2 Additional data ...................................................................................................25 5.3 Input data...........................................................................................................25 5.3.1 Test item ............................................................................................................25 5.3.2 Test procedure...................................................................................................25 5.4 Analysis results ..................................................................................................27

6 REFERENCES...................................................................................................30

ROBUST project Page 1



1 INTRODUCTION

Within ROBUST project WP5, CIDAUT carried out simulations of a vehicle, impacting a steel barrier. The impact conditions were according to EN1317 – Part 2 specifications for TB11 crash test, with an initial speed of 100 km/h and an angle of 20 degrees. The vehicle used for the test simulations was a version of the Geometro model specifically adapted for PAM-CRASH simulation code. The objectives of the WP5 project are:

• Evaluation and enhancement of the use of computational mechanics to complement experimental activity

• Criteria and procedures for the validation of computational mechanics results through comparison with test results

• Reconstruction of real life accidents

• Identification of activity needed for further enhancement of the use of computational mechanics

The simulations reported are focused on the first objective. The work included variety of simulations considering different parameters: material, length, bolt modelling, etc. Also reduced simulations were peformed. This report documents the simulations performed on the B1 steel safety barrier.




2 SUMMARY AND CONCLUSIONS

2.1 Summary

The following simulations have been performed for the B5 barrier

Case Barrier Test Name id. Chapter

1 B1 ESP TB11 B1-MetroPAM-TB11 full length

Chapter 3

2 B1 ESP TB11 B1-MetroPAM-TB11 reduced length

Chapter 4

3 B1 ESP TB11 B1-MetroPAM-TB11. Posts Chapter 5

The main results are summarised inTable 2-1 below.

Table 2-1 Results from simulations with the B5 temporary vertical concrete safety barrier

Case ASI THIV [km/h]

PHD [g]

Working Width [mm]

Exit speed [km/h]

Exit angle [deg]

Trajectory Detailed description

1.1 0.59 22.2 25.3 1060 66.24 12.2 OK Chapter 3

1.2 0.60 20.7 6.4 1100 67.68 12.4 OK Chapter 3

2.1 0.52 19.1 6.5 1119 78.5 11.5 OK Chapter 5

2.2 Conclusions




3 BARRIER – B1 VS GEOMETRO. FULL LENGTH

3.1 General

The barrier used in the simulation represented the B1 barrier (ESP steel barrier, N2). The vehicle model was a light passenger vehicle, developed by CIDAUT for simulation with the PAM-CRASHTM code. This vehicle model has the same overall geometry as the Geometro model which was supplied as part of the project, and complies with the vehicle characteristics specified by EN1317 for 900-kg vehicle.

The simulation scenario consisted of the vehicle impacting the barrier with an initial speed of 100 km/h and an angle of 20 degrees.

The characteristics specific to this simulation are:

� The barrier was modelled using a non-linear material model and represented by shell elements for all steel pieces that reproduced its geometry.

� The full length of the barrier was modelled.

� Post embedment in soil was modelled by fixing posts 200 below ground level.

� Friction between the vehicle and the barrier was set to 0.

� Friction between the ground and the tyres was set to 0.6

3.2 Additional data

The following data and files supplement the result presentation of the simulation as presented in this chapter.

Excel worksheet file:

Rawdata file: B1-metroPAM-c1.zip

Animations:

- front view B1-c1_front.avi

- side view B1-c1_side.avi

- top view B1-c1_top.avi

-perspective B1-c1_iso.avi




3.3 Input data

3.3.1 Test item

Test item: ESP – N2

Vehicle: Geometro - PAMCRASH

3.3.2 Test procedure

1) Test type – TB11

Impact speed: 103.5 km/h

Impact angle: 20 degrees

Impact point: About 26 metres from the beginning of the VRS

Spinning wheels: No

Inertial vehicle test mass: 904 kg

2) VRS model

Barrier type: ESP – N2

Number of posts: 39

Spacing: 2 m

Total length: 76 m

Element formulation/type: Shell elements.

Connection/Joints: Tied joints with failure

Foundation: Posts fixed to the soil

End anchoring: None

Soil (type and formulation): Posts fixed to the soil

Roadway: Modelled as rigid wall

3) Vehicle model

Light passenger vehicle, developed by CIDAUT for simulation with PAM-CRASHTM.

3.3.3 Analysis data

Timestep: Between 2 and 3 E-06

Precision: Single




Friction barrier/vehicle (static coefficient): 0

Friction barrier/vehicle (dynamic coefficient) 0

Friction wheel/ground (static coefficient) 0.6

Friction wheel/ground (dynamic coefficient) 0.6

Accelerometer location (mounting block) Coincident with vehicle cog: Distance 16 mm in Y-direction, less than 1 mm in X and Z directions.

Sampling rate

Friction other:

1.0 E-4 for THP

NA




Table 3.1 Model description.

ESP steel safety barrier Computer model, VRS for roads

Model description Nodes Shell elements Spot welds Materials

142486 134074 NA 1 Other

The safety barrier was modelled with shell elements. Contact with no friction was modelled between the vehicle and the concrete barrier.

Table 3.2 Material characteristic.

Vehicle restraint system Part E-Module [MPa] Density [kg/m3] Yield Stress [MPa] Ultimate Stress

[MPa] Failure Strain [-] Comments

Case c1.1. All parts

210000 7850 Multiple point curve

Multiple point curve

Non-linear


210000 7850 300.0 450.0 0.3 Non-linear

Strain Rate Stress vs. strain values

NA NA




3.4 Analysis results

1) VRS

Maximum global dynamic deflection: 1004 mm

Working width: 1060 mm

Maximum global permanent deflection: 788 mm at the end of simulation

Length of contact: 10.4 m approximately

Major parts fractured or detached: 6 posts detached from beam

Description of damage to test items: No

Ground anchorage’s meets design levels: Yes

Plot of test items:

2) Vehicle

Exit speed: 66.24 km/h

Exit angle: 12.2 degrees

Rebound distance: NA

Vehicle breaches barrier: No

Vehicle passes over the barrier: No

Vehicle within CEN “box”: NA

Vehicle rolls over after impact: No

Damage to test vehicle:




3) General description of vehicle trajectory:

The vehicle hits the VRS at a velocity of 100 km/h and at an angle of 20 degrees. The vehicle leaves the VRS at an angle of 3.7 degrees. The trajectory is good in the simulation.

Vehicle damage TAD: NA

Vehicle damage VDI: NA

Vehicle cockpit def. index VCDI: NA

Major parts of vehicle detached: No

Plots of the vehicle:

4) Assessment of the impact severity

Impact severity for this model was assessed for two cases, c1.1 and c1.2, that differ only in the material law.

Post-processing procedure Accelerometer and rotation data, CFC 180. input into TRAP

Acceleration severity index, ASI: 0.59

Acceleration graphs: Yes

THIV: 22.2 km/h

Time of flight: 134 ms

Post-impact head deceleration, PHD: 25.3 g

Flail space: 0.6 x 0.3 m

Post-processing procedure Accelerometer and rotation data, CFC 180. input into TRAP



THIV: 20.7 km/h

Time of flight: 139 ms



5) General statement

From the results above, it can be concluded that the crash protection system fulfils the requirements of the CEN standard with the exception of the PHD severity index in one of the cases.




Table 3.3 Vehicle - Front view.

Time 0.00 Time 0.080

Time 0.160 Time 0.240

Time 0.320 Time 0.400

Time 0.480 Time 0.560




Table 3.4 Vehicle – Side view.


Time 0.160 Time 0.240

Time 0.320 Time 0.400

Time 0.480 Time 0.560




Table 3.5 Vehicle - Top view


Time 0.160 Time 0.240

Time 0.320 Time 0.400

Time 0.480 Time 0.560




Table 3.6 Vehicle – Iso View


Time 0.160 Time 0.240

Time 0.320 Time 0.400

Time 0.480 Time 0.560




Table 3.7 Vehicle damage.

Top view Bottom view

Side view Side view

View View




4 BARRIER – B1 VS GEOMETRO. REDUCED LENGTH

4.1 General

The barrier used in the simulation represented the B1 barrier (ESP steel barrier, N2). The vehicle model was a light passenger vehicle, developed by CIDAUT for simulation with the PAM-CRASHTM code. This vehicle model has the same overall geometry as the Geometro model which was supplied as part of the project, and complies with the vehicle characteristics specified by EN1317 for 900-kg vehicle.

The simulation scenario consisted of the vehicle impacting the barrier with an initial speed of 100 km/h and an angle of 20 degrees.

The characteristics specific to this simulation were the ones deemed to provide a better agreement with the experimental crash test. They are:

� The barrier was modelled using a non-linear material model and represented by shell elements for all steel pieces that reproduced its geometry

� Part of the full length of the barrier was not modelled, but substituted by non-linear springs that behaved according to the same force-displacement law as the removed sections.

� Post embedment in soil was modelled by fixing posts 200 below ground level.

� Friction between the vehicle and the barrier was set to 0.

� Friction between the ground and the tyres was set to 0.6

4.2 Additional data



Rawdata file: B1-metroPAM-c1.zip

Animations:

- front view B1-c2_front.avi

- side view B1-c2_side.avi

- top view B1-c2_top.avi

-perspective B1-c2_iso.avi

4.3 Input data

4.3.1 Test item




Test item: ESP – N2 Temporary

Vehicle: Geometro - PAMCRASH Geometro


4) Test type – TB11

Impact speed: 103.5 km/h

Impact angle: 20 degrees

Impact point: About 26 metres from the beginning of the VRS, 8 m from the beginning of the reduced section

Spinning wheels: No

Inertial vehicle test mass: 904 kg

5) VRS model

Barrier type: ESP – N2

Number of posts: 12

Spacing: 2 m

Total length: 15 m

Element formulation/type: Shell elements.

Connection/Joints: Tied joints with failure

Foundation: Posts fixed to the soil

End anchoring: Non-linear springs

Soil (type and formulation): NA

Roadway: Modelled as rigid wall

6) Vehicle model

Light passenger vehicle, developed by CIDAUT for simulation with PAM-CRASHTM.

4.3.3 Analysis data

Timestep: Between 2 and 3 E-06

Precision: Single

Friction barrier/vehicle (static coefficient): 0.3

Friction barrier/vehicle (dynamic coefficient) 0.3

Friction wheel/ground (static coefficient) 0.6

Friction wheel/ground (dynamic coefficient) 0.6

Accelerometer location (mounting block) Coincident with vehicle cog




Sampling rate

Friction other:

1.0 E-4 for THP

NA





Temporary Vertical Concrete Safety Barrier (B5) Computer model, VRS for roads


142486 134074 NA 1 Other

The safety barrier was modelled with shell elements. Contact with no friction was modelled between the vehicle and the concrete barrier. Barrier sections away from the impact area were replaced with non-linear springs..

Table 4.2 Material characteristic.






Non-linear


NA NA





6) VRS

Maximum global dynamic deflection: 1061 mm

Working width: 1119 mm

Maximum global permanent deflection: 1240 mm at the end of simulation

Length of contact: 10.4m approximately

Major parts fractured or detached: 6 posts detached from beam

Description of damage to test items: No

Ground anchorage’s meets design levels: Yes

Plot of test items:

7) Vehicle

Exit speed: 78.5 km/h

Exit angle: 11.5 degrees

Rebound distance: NA

Vehicle breaches barrier: No

Vehicle passes over the barrier: No

Vehicle within CEN “box”: NA

Vehicle rolls over after impact: No

Damage to test vehicle:




8) General description of vehicle trajectory:

The vehicle hits the VRS at a velocity of 100 km/h and at an angle of 20 degrees. The vehicle leaves the VRS at an angle of 3.7 degrees. The trajectory is good in the simulation. It is essentially similar to the one reported in case 1, but with a larger change of velocity due to the friction coefficient.

Vehicle damage TAD: NA

Vehicle damage VDI: NA

Vehicle cockpit def. index VCDI: NA

Major parts of vehicle detached: No

Plots of the vehicle:

9) Assessment of the impact severity

Post-processing procedure Accelerometer and rotation data, sampled at 10 KHz, CFC180, input into TRAP



THIV: 19.1 km/h

Time of flight: 133.4 ms



10) General statement

From the results above, it can be concluded that the crash protection system fulfils the requirements of the CEN standard.




Table 4.3 Vehicle - Front view.


Time 0.160 Time 0.240

Time 0.320 Time 0.400

Time 0.480 Time 0.560




Table 4.4 Vehicle – Side view.


Time 0.160 Time 0.240

Time 0.320 Time 0.400

Time 0.480 Time 0.560




Table 4.5 Vehicle - Top view


Time 0.160 Time 0.240

Time 0.320 Time 0.400

Time 0.480 Time 0.560




Table 4.6 Vehicle – Iso View


Time 0.160 Time 0.240

Time 0.320 Time 0.400

Time 0.480 Time 0.560




Table 4.7 Vehicle damage.

Top view Bottom view

Side view Side view

View View




5 BARRIER – B1. REDUCED MODELS (SIGMA POSTS)

5.1 General

The steel ESP barrier comprises sigma-shaped posts. A detailed study was performed on these posts, based also on information from static pull-push tests.

The characteristics specific to this simulation are:

� The barrier posts were modelled by shell elements. To model the embedment, their lower part was rigidly fixed in the ground, at a certain depth below ground level.

� Force was applied on posts externally and the relationships between forces and displacements were measured.

5.2 Additional data



Rawdata file:

Animations:

- iso view B1-c31_iso.avi: pull test, concreted post, direction Y

- iso view B1-c32_iso.avi: pull test, concreted post, direction X

- side view B1-c33_side.avi: push test, 100mm-driven post, direction Y



5.3 Input data

5.3.1 Test item

Test item: ESP-N2 barrier sigma post

Vehicle: -


7) Test type – Pull test





Temporary Vertical Concrete Safety Barrier (B5) Computer model, VRS for roads


2843 1802 NA 1 Other

One sigma post fixed into the ground at a certain depth.

Table 5.2 Material characteristic – Steel and plastic sections.



B1 post



Non-linear


NA NA

Force Y Force Y Force Y

550 mm

100 mm 150 mm 200 mm





Table 5.3 Post on rigid post foundation pull test. Test for the comparison of the behaviour of two material models. Direction Y




Table 5.4 Post on rigid post foundation pull test. Test for the comparison of the behaviour of two material models. Direction Y.




Table 5.5. Test on post fixed under ground level. Push test for the comparison of the

behaviour of different anchoring depths. Direction Y




6 REFERENCES

Ref. 1 EN 1317-1: Road restraint systems – Part 1: Terminology and general criteria for test methods. European Committee for Standardization, April 1998.

Ref. 2 EN 1317-2: Road restraint systems – Part 2: Performance classes, impact test acceptance criteria and test methods for safety barriers. European Committee for Standardization, April 1998

Documents

ROBUST PROJECT CIDAUT WP5 - Computational Mechanics …€¦ · · 2006-05-22ROBUST PROJECT CIDAUT WP5 - Computational Mechanics B1 Barrier – Steel N2 MAIN REPORT ... 3.3.3 Analysis