CIDAUT Concrete 5-011a - Statens vegvesen · WP5 - Computational Mechanics B5 - Temporary Vertical Concrete Safety Barrier MAIN REPORT Volume 1 of 1 ... 3.1 1.68 28.4 22.6 450 86.4

ROBUST PROJECT

CIDAUT WP5 - Computational Mechanics B5 - Temporary Vertical Concrete Safety Barrier MAIN REPORT Volume 1 of 1

November 2005 Doc. No.: ROBUST-5-011a – Rev 0

Main Report

286-2-1-no-en

Report title:

WP5 - Computational Mechanics B5 Concrete Barrier

Client:

CIDAUT

Doc. no.:

ROBUST-5-011a

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 B5 temporary vertical concrete safety barrier. The simulations were performed by CIDAUT.

Keywords:

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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-5-011a – Rev 0

WP5 - Computational Mechanics B5 Concrete Barrier MAIN REPORT

CONTENTS

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

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

3 BARRIER – B5 VS GEOMETRO FOR THE ANALYSIS OF OUTPUT SIGNALS. 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........................................................................................................5 3.4 Analysis results ....................................................................................................7

4 BARRIER – B5 VS GEOMETRO. BASELINE MODEL.......................................15 4.1 General ..............................................................................................................15 4.2 Additional data ...................................................................................................15 4.3 Input data...........................................................................................................15 4.3.1 Test item ............................................................................................................15 4.3.2 Test procedure...................................................................................................16 4.3.3 Analysis data......................................................................................................16 4.4 Analysis results ..................................................................................................18

5 BARRIER – B5 VS GEOMETRO, VARIATION OF FRICTION COEFFICIENT...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...................................................................................................26 5.3.3 Analysis data......................................................................................................26 5.4 Analysis results ..................................................................................................28

6 BARRIER – B5 VS GEOMETRO. VARIATION OF KINETIC ENERGY..............35 6.1 General ..............................................................................................................35 6.2 Additional data ...................................................................................................35 6.3 Input data...........................................................................................................35 6.3.1 Test item ............................................................................................................35 6.3.2 Test procedure...................................................................................................36 6.3.3 Analysis data......................................................................................................36 6.4 Analysis results ..................................................................................................38

7 BARRIER – B5 VS GEOMETRO., LS-DYNA SIMULATION...............................46 7.1 General ..............................................................................................................46 7.2 Additional data ...................................................................................................46 7.3 Input data...........................................................................................................46 7.3.1 Test item ............................................................................................................46 7.3.2 Test procedure...................................................................................................47 7.3.3 Analysis data......................................................................................................47 7.4 Analysis results ..................................................................................................49

8 REFERENCES...................................................................................................56

ROBUST project Page 1



1 INTRODUCTION

Within ROBUST project WP5, CIDAUT carried out simulations of a vehicle, impacting a vertical concrete 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 topics addressed include the data output and post-processing procedure. This report documents the simulations performed on the B5 temporary vertical concrete 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 B5 Concrete TB11 B5-MetroPAM-TB11 output signals

Chapter 3

2 B5 Concrete TB11 B5-MetroPAM-TB11 Chapter 4

3 B5 Concrete TB11 B5-MetroPAM-TB11 modified friction

Chapter 5

4 B5 Concrete TB11 B5-MetroPAM-TB11 modified kinetic energy

Chapter 6

5 B5 Concrete TB11 GeoMetro LS-DYNA Chapter 7

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 1.67 28.2 22.2 450 90.4 5.0 OK Chapter 3

2 1.71 29.4 20.8 450 83.7 3.7 OK Chapter 4

3.1 1.68 28.4 22.6 450 86.4 4.4 OK Chapter 5

3.2 1.66 28.0 24.2 450 89.6 4.9 OK Chapter 5

4.1 1.71 28.7 21.7 450 91.4 5.2 OK Chapter 6

4.2 1.75 29.3 21.2 450 93.2 5.3 OK Chapter 6

4.3 1.81 30.2 20.6 450 96.1 5.2 OK Chapter 6

5 1.73 31.2 19.2 450 75.6 5.5 OK Chapter 7

2.2 Conclusions

Simulation results, in terms of acceleration and velocity time histories, are representative of the behaviour of TB11 test vehicle in crash test. The post-processing of the results has additional requirements in terms of output process and data filtering in order to obtain adequate calculation of the severity indices.




3 BARRIER – B5 VS GEOMETRO, ANALYSIS OF OUTPUT SIGNALS.

3.1 General

In this stage, a complete set of simulations were performed in order to determine the most suitable way to obtain, store and process outputs from the simulation program so that a reliable assessment could be made. The results obtained using the finally chosen parameters are the ones included in this chapter. For additional information, refer to document ROBUST-5-011b.

The barrier used in the simulation represented the ‘Temporary Vertical Concrete Safety Barrier’ (B5) used in Round Robin Testing. 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 as a rigid body, rigidly fixed in space, and represented by shell elements that reproduced its outer surface

� 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: B5-metroPAM-c1.zip

Animations:

- front view B5-c1_front.avi

- side view B5-c1_side.avi

- top view B5-c1_top.avi

-perspective B5-c1_iso.avi




3.3 Input data

3.3.1 Test item

Test item: Temporary vertical concrete safety barrier (B5)

Vehicle: Geometro

Drawings: From Marshalls

3.3.2 Test procedure

1) Test type – TB11

Impact speed: 100 km/h

Impact angle: 20 degrees

Impact point: About 3.2 metres from the beginning of the VRS

Spinning wheels: No

Inertial vehicle test mass: 874 kg

2) VRS model

Barrier type: Temporary Vertical Concrete Safety Barrier (B5)

Number of posts: None

Spacing: None

Total length: 11 m

Element formulation/type: Shell elements.

Connection/Joints: None

Foundation: None. Complete barrier fixed in space

End anchoring: NA

Soil (type and formulation): NA

Roadway: Modelled as rigid wall

3) Vehicle model

Light passenger vehicle, developed by CIDAUT for simulation with PAM-CRASHTM. Same overall geometry as the Geometro model, and complies with the vehicle characteristics specified by EN1317 for 900-kg vehicle. Validation report available.




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.

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

Model description Nodes Shell elements Spot welds Materials

15462 14516 NA 1 Other

The concrete barrier was modelled with dimensions 0.8m height, 0.45m depth and 11m length. In order to reproduce the perfectly rigid behaviour intended in crash tests, it was modelled as a rigid body with all degrees of freedom fixed. Contact with friction was modelled between the vehicle and the concrete barrier. To take into account this interaction, shell elements were used.

Table 3.2 Material characteristic.

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

[MPa] Failure Strain [-] Comments

B5 Concrete barrier

NA NA - - - Elastic

Strain Rate Stress vs. strain values

NA NA




3.4 Analysis results

1) VRS

Maximum global dynamic deflection: 0 mm

Working width: 450 mm

Maximum global permanent deflection: 0 mm

Length of contact: 3.31m approximately

Major parts fractured or detached: No

Description of damage to test items: No

Ground anchorage’s meets design levels: NA

Plot of test items: Table 4.3 - Table 4.6

2) Vehicle

Exit speed: 90.4 km/h

Exit angle: 5.0 degrees

Rebound distance: NA

Vehicle breaches barrier: No

Vehicle passes over the barrier: No

Vehicle within CEN “box”: Simulation was not run for a long enough period to make the assessment. Though, shallow exit angle indicates it most probably complies

Vehicle rolls over after impact: No

Damage to test vehicle: Table 4.7




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: Table 4.7

4) Assessment of the impact severity

Impact severity for this model was assessed through three different procedures for data processing.

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

Acceleration severity index, ASI: 1.67

Acceleration graphs: Yes

THIV: 28.3 km/h

Time of flight: 73.2 ms

Post-impact head deceleration, PHD: 26.2 g

Flail space: 0.6 x 0.3 m

Post-processing procedure Data sampled at 10 KHz, then processed to have a constant time interval of 10 KHz, and input into TRAP as raw data



THIV: 28.2 km/h




Post-processing procedure Data sampled 10 KHz, processed to have a constant time interval of 10 KHz, filtered CFC180, and finally input into TRAP



THIV: 28.2 km/h







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 severity indices.

The comparison of the values obtained from the different post-processing led to the adoption of the output parameters for the subsequent simulations.




Table 3.3 Vehicle - Front view.

Time 0.00 Time 0.048

Time 0.096 Time 0.144

Time 0.192 Time 0.240




Table 3.4 Vehicle – Side view.


Time 0.096 Time 0.144

Time 0.192 Time 0.240




Table 3.5 Vehicle - Top view


Time 0.096 Time 0.144

Time 0.192 Time 0.240




Table 3.6 Vehicle – Iso View


Time 0.096 Time 0.144

Time 0.192 Time 0.240




Table 3.7 Vehicle damage.

Top view Bottom view

Side view Side view

View View




4 BARRIER – B5 VS GEOMETRO. BASELINE MODEL

4.1 General



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


� Friction between the vehicle and the barrier was set to 0.3.


4.2 Additional data




Animations:





4.3 Input data

4.3.1 Test item


Vehicle: Geometro










Spinning wheels: No


5) VRS model



Spacing: None

Total length: 11 m




End anchoring: NA



6) Vehicle model

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

4.3.3 Analysis data


Precision: Single

Friction barrier/vehicle (static coefficient): 0.3

Friction barrier/vehicle (dynamic coefficient) 0.3



Accelerometer location (mounting block) Coincident with vehicle cog

Sampling rate

Friction other:

1.0 E-4 for THP

NA







15462 14516 NA 1 Other





B5 Concrete barrier

NA NA - - - Elastic


NA NA





6) VRS









7) Vehicle













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.







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



THIV: 29.4 km/h











Time 0.096 Time 0.144

Time 0.192 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Side view Side view

View View




5 BARRIER – B5 VS GEOMETRO, VARIATION OF FRICTION COEFFICIENT

5.1 General



Once that the barrier and vehicle model were checked, simulation case 3 analyses the effect of variations in friction coefficient.



� Friction between the vehicle and the barrier was set to 0.15 and 0, from the initial value of 0.3.


5.2 Additional data




Animations:





5.3 Input data

5.3.1 Test item


Vehicle: Geometro










Spinning wheels: No


8) VRS model



Spacing: None

Total length: 11 m




End anchoring: NA



9) Vehicle model


5.3.3 Analysis data


Precision: Single

Friction barrier/vehicle (static coefficient): 0.15, 0

Friction barrier/vehicle (dynamic coefficient) 0.15, 0




Sampling rate

Friction other:

1.0 E-4 for THP

NA







15462 14516 NA 1 Other


Table 5.2 Material characteristic – Steel and plastic sections.



B5 Concrete barrier

NA NA - - - Elastic


NA NA





11) VRS









12) Vehicle

Case 3.1. Friction coefficient 0.15









Case 3.2. Friction coefficient 0.













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. Only a slight difference in the exit trajectory appear between case 3.1 and 3.2, and between them and case 2.







Impact severity for this model was assessed for cases 3.1 and 3.2.

Case 3.2. Friction coefficient 0.15

Post-processing procedure

Accelerometer and rotation data, sampled at 10 KHz, CFC180, input into TRAP



THIV: 28.4 km/h




Case 3.2. Friction coefficient 0.

Post-processing procedure

Accelerometer and rotation data, sampled at 10 KHz, CFC180, input into TRAP



THIV: 28.0 km/h











Time 0.096 Time 0.144

Time 0.192 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.240

Time 0.336 Time 0.384

Compared trajectories: case 3.1 (blue), 3.2 (red) and 2 (green)






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Side view Side view

View View




6 BARRIER – B5 VS GEOMETRO. VARIATION OF KINETIC ENERGY

6.1 General


The simulation scenario consisted of the vehicle impacting the barrier with an angle of 20 degrees, and increased values for initial speed (102, 104, 107 km/h) and increased total vehicle mass (964 kg).





6.2 Additional data




Animations:





6.3 Input data

6.3.1 Test item


Vehicle: Geometro







Impact speed: 102, 104, 107 km/h



Spinning wheels: No


11) VRS model



Spacing: None

Total length: 11 m




End anchoring: NA



12) Vehicle model


6.3.3 Analysis data


Precision: Single






Sampling rate

Friction other:

1.0 E-4 for THP

NA







15462 14516 NA 1 Other





B5 Concrete barrier

NA NA - - - Elastic


NA NA





16) VRS









17) Vehicle




















Impact severity for this model was assessed for the three different cases.

Case 4.1. 102 km/h

Post-processing procedure Sampled 10 KHz, CFC180, TRAP



THIV: 28.7 km/h




Case 4.1. 104 km/h




THIV: 29.3 km/h




Case 4.1. 107 km/h




THIV: 30.2 km/h














Time 0.096 Time 0.144

Time 0.192 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.200

Differences in cog trajectories (represented: case 4.3, black; case 4.2 red; case 4.1 blue; case 2 green) and vehicle damages are nearly negligible.






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Side view Side view

View View




7 BARRIER – B5 VS GEOMETRO., LS-DYNA SIMULATION

7.1 General

The barrier used in the simulation represented the ‘Temporary Vertical Concrete Safety Barrier’ (B5) used in Round Robin Testing. The vehicle model was the a LS-DYNA TB11 model. It was based on the Geometro model supplied as part of the project. Then some modifications were applied, in order to study the possibility to tune the model for a better agreement with test vehicles. The vehicle model complies with the vehicle characteristics specified by EN1317 for 900-kg vehicle.






7.2 Additional data



Rawdata file: B5-metroc5.zip

Animations:





7.3 Input data

7.3.1 Test item


Vehicle: Geometro










Spinning wheels: No


14) VRS model



Spacing: None

Total length: 11 m




End anchoring: NA



15) Vehicle model

Light passenger vehicle, developed by CIDAUT for simulation with PAM-CRASHTM. Same overall geometry as the Geometro model, and complies with the vehicle characteristics specified by EN1317 for 900-kg vehicle. Validation report available.

7.3.3 Analysis data


Precision: Single





Accelerometer location (mounting block)

Sampling rate

Friction other:

1.0 E-5

NA







15462 14516 NA 1 Other

The concrete barrier was modelled with dimensions 0.8m height. In order to reproduce the perfectly rigid behaviour intended in crash tests, it was modelled as a rigid body with all degrees of freedom fixed. Contact with friction was modelled between the vehicle and the concrete barrier. To take into account this interaction, shell elements were used.




B5 Concrete barrier

NA NA - - - Elastic


NA NA





21) VRS









22) Vehicle




















Impact severity for this model was assessed through three different procedures for data processing.

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



THIV: 31.2 km/h

Time of flight: Ms










Time 0.100 Time 0.140

Time 0.200 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Time 0.096 Time 0.144

Time 0.192 Time 0.240






Side view Side view

View View




8 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

CIDAUT Concrete 5-011a - Statens vegvesen · WP5 - Computational Mechanics B5 - Temporary Vertical Concrete Safety Barrier MAIN REPORT Volume 1 of 1 ... 3.1 1.68 28.4 22.6 450 86.4