ROBUST PROJECT Norwegian Public Roads Administration / Force Technology Norway AS Volume 1 of 1 April 2005 Doc. No.: ROBUST-05-009/TR-2005-0012 - Rev. 0 286-2-1-no-en
Main Report Report title: Simulation company: Norwegian Public Roads Administration / Force Technology Norway AS Project no.: 14081 Abstract: Doc. no.: ROBUST-05-009/TR-2005-0012 Reporter(s): Rune Gladsø Fredrik Sangö On behalf of the Norwegian Public Roads Administration, Force Technology has performed an evaluation of the 10 ton Rigid HGV developed by POMI. This has been performed as a part of the Robust project. The vehicle is within the vehicle specifications given in Table 1 in EN1317-1, Ref/1/. One TB42 simulation of the vehicle crashing into the Round Robin barrier has been performed. The vehicle trajectory and the deformation of the vehicle are reasonable in the simulation. However, no full-scale test has been performed for this configuration, so the evaluation is only based on Force Technology s general knowledge about crash tests and computer simulations of barriers. In addition some general comments of the model are given. The evaluation shown that the 10 ton Rigid HGV vehicle model is acceptable to use for computer simulations of rigid barriers. Keywords: Vehicle Restraint System TB52 test FE Analyses and model evaluation Restricted Internal Free distribution Ref. allowed Rev. no. Date Prepared by Checked by Approved by Reason for revision 0 01.04.2005 Rune Gladsø Fredrik Sangö K. Johannessen A 28.02.05 Rune Gladsø Fredrik Sangö K. Johannessen Issued for Comment 286-2-1-no-en
ROBUST project Page i CONTENTS 1 INTRODUCTION...1 2 SUMMARY AND CONCLUSIONS...2 3 EVALUATION OF VEHICLE ACCORDING TO EN1317-1...3 4 TB42 SIMULATION OF THE ROUND ROBIN BARRIER...5 5 GENERAL COMMENTS TO THE FE-MODEL...14 6 CALCULATION OF KINETIC ENERGY AND THEORETICAL AVERAGE FORCE15 7 REFERENCES...16
ROBUST project Page 1 1 INTRODUCTION This report gives an evaluation of the FE-model of the 10 ton Rigid HGV developed by POMI. The vehicle is check according to the vehicle specification given in EN1317, 0, regarding: Vehicle mass Wheel track Wheel radius Wheelbase Ground clearance COG The model is also evaluated based on Force Technology s general knowledge about crash tests and computer simulations of barriers, regarding element types, material types and mesh density. In addition, one TB42 simulation of the vehicle crashing into the Round Robin barrier has been performed in order to evaluate trajectory and deformation of the vehicle.
ROBUST project Page 2 2 SUMMARY AND CONCLUSIONS On behalf of the Norwegian Public Roads Administration, Force Technology has performed an evaluation of the 10 ton Rigid HGV developed by POMI. This has been performed as part of the Robust project. The vehicle is within the vehicle specifications given in Table 1 in EN1317-1, Ref/1/. One TB42 simulation of the vehicle crashing into the Round Robin barrier has been performed. The vehicle trajectory and the deformation of the vehicle are reasonable in the simulation. However, no full-scale test is available for this configuration, so the evaluation is only based on Force Technology s general knowledge about crash tests and computer simulations of barriers. The contact force between the barrier and the vehicle is evaluated based on the theoretical approach given in Annex B of EN1317. This study showed that the vehicle behaves somewhat rigidly in the crash simulation. However, the methodology given in Annex B of EN1317 is only an approximation. The evaluation shown that the 10 ton Rigid HGV vehicle model is acceptable to used for computer simulations of rigid barriers. Table 2.1 below gives the chapter the different investigated issues are discussed. The main results are summarised in Table 2.2 below. Table 2.1 Chapter overview. Chapter Description Chapter 3 Evaluation of vehicle according to en1317-1 Chapter 4 TB42 simulation of the Round Robin barrier Chapter 5 General comments to the FE-model Chapter 6 Calculation of kinetic energy and theoretical average force Table 2.2 Results from simulation. Case ASI [-] THIV [km/h] PHD [g] Working width [mm] Exit speed [km/h] Exit angle [deg] Trajectory Detailed description 1 605 (W1/W2) 65 9 Good Chapter 4
ROBUST project Page 3 3 EVALUATION OF VEHICLE ACCORDING TO EN1317-1 The computer model is compared to the vehicle specifications as given Table 1 in EN1317-1. The vehicle specifications and the comparison are presented in Table 3.1. The vehicle satisfied all the specifications described in 0. Some additional dimensions of vehicle are also presented in Table 3.1.
ROBUST project Page 4 Table 3.1 Vehicle specification Rigid HGV Rigid HGV 10 ton Side view L Front view W cog H WR HL CGZ CGX FH T WB Vehicle weight Model weight [kg] Weight [kg] 1 Min. weight [kg] 1 Max. weight [kg] 1 Acceptable 10000 10000 9700 10300 Yes Vehicle dimension Wheel track, T [mm] Wheel track [mm] 1 Min. wheel track [mm] 1 Max. wheel track [mm] 1 Acceptable Front 1980/ Back 2070 2000 1700 2300 Yes Wheel radius [mm] Wheel radius [mm] 1 Min. wheel radius [mm] 1 Max. wheel radius [mm] 1 Acceptable 449 460 391 529 Yes Wheel base, WB [mm] Wheel radius [mm] 1 Min. wheel radius [mm] 1 Max. wheel radius [mm] 1 Acceptable 4455 4600 3910 5290 Yes Vehicle width, W [mm] Vehicle width [mm] 1 Min. vehicle width [mm] 1 Max. vehicle width [mm] 1 Acceptable 2486 - - -! Vehicle height, H [mm] Vehicle height [mm] 1 Min. vehicle height [mm] 1 Max. vehicle height [mm] 1 Acceptable 2885 -! Vehicle length, L [mm] Vehicle length [mm] 1 Min. vehicle length [mm] 1 Max. vehicle length [mm] 1 Acceptable 8315 - - -! Vehicle front height, FH [mm] Vehicle length [mm] 1 Min. vehicle length [mm] 1 Max. vehicle length [mm] 1 Acceptable 649 580 493 667 Yes Centre of gravity location Longitudinal distance (CGX) [mm] Longitudinal distance (CGX) [mm] 1 Min longitudinal distance (CGX) [mm] 1 Max. longitudinal distance (CGX) [mm] 1 Acceptabl e 2701 2700 2295 3105 Yes Lateral distance (CGY) [mm] Lateral distance (CGY) [mm] 1 Min lateral distance (CGY) [mm] 1 Max. lateral distance (CGY) [mm] 1 Acceptabl e 0 0-100 100 Yes Height above ground (CGZ) [mm] Height above ground (CGZ) [mm] 1 Min height above ground (CGZ) [mm] 1 Max. height above ground (CGZ) [mm] 1 Acceptabl e 1242 - - -! Height above ground/load (HL) [mm] Height above ground (HL) [mm] 1 Min height above ground (HL) [mm] 1 Max. height above ground (HL) [mm] 1 Acceptabl e 1540 1500 1275 1725 Yes 1 According to Standard
ROBUST project Page 5 4 TB42 SIMULATION OF THE ROUND ROBIN BARRIER This chapter describes the results obtained from the simulation of a rigid HGV (10 tonnes) hitting the Round Robin Barrier with an angle of 15 degrees and a velocity of 70 km/h. a) Simulation company Name: Force Technology AS Address: Claude Monets alle 5, 1300 Sandvika, Norway Telephone: +(47) 67 55 38 00 Facsimile number +(47) 67 55 38 10 b) Client Name: Norwegian Public Roads Administration Address: Brynsengfaret 6A, 0667 Oslo, Norway Telephone number: (+47) 22 07 35 00 c) Test item Test items: Round Robin Concrete Barrier Vehicle: Rigid HGV Drawings: Table 4.1 d) Additional data The following data and files supplement the result presentation of the simulation as presented in this chapter. Excel worksheet file: Rawdata file: Animations: - front view Lorry-10t_Front_view.avi - side view Lorry-10t_Side_view.avi - top view Lorry-10t_Top_view.avi - perspective Lorry-10t_Perspective_view.avi
ROBUST project Page 6 e) Test procedure 1) Test type TB 42 Impact speed: 70 km/h Impact angle: 15 degrees Inertial vehicle test mass: 10000 kg 2) Modelling The barrier consists of a 0,8 meter high concrete block with a length of 24 meters. The block behaves rigidly in the simulation as it is fixed at ground level. For additional dimensions reference is made to Table 4.1 3) Vehicle The FE-model is received from POMI with no further documentation. f) Simulation results 1) Test items Maximum global dynamic deflection: < 1mm (rigid VRS) Working width: 605 mm W1/W2 Maximum global permanent deflection: 0 mm Length of contact: ca 3 m Impact point: 12 meter upstream beginning of barrier Major parts fractured or detached: No Description of damage to test items: Ground anchorage s meets design levels: Plot of test items: Table 4.4- Table 4.8 2) Vehicle Impact speed: 70 km/h % difference from target speed: 0 Impact angle: 15 deg. % difference from target angle: 0 Within tolerance limits: Yes Exit speed: 65 km/h Exit angle: 9 deg
ROBUST project Page 7 Rebound distance: Vehicle breaches barrier: Vehicle passes over the barrier: Vehicle within CEN box : Vehicle rolls over after impact: No No Yes - See general statement No Damage to test vehicle: Table 4.8 General description of vehicle trajectory: The vehicle hits the barrier 12 meter upstream the beginning of the barrier. The vehicle starts to rotate counter-clockwise. The vehicle leaves the barrier with an angle of 9 degrees. The trajectory is good in the simulation. Vehicle damage TAD: Vehicle damage VDI: Vehicle cockpit def. index VCDI: Major parts of vehicle detached: No Plot of vehicle: Table 4.8 3) Assessment of the impact severity Acceleration severity index, ASI: Post-impact head deceleration, PHD: Flail space: Time of flight: THIV: Acceleration graphs: g) General statement Based on the above it can be concluded that the crash protection system fulfils the requirements of the CEN standard. The working width is decided by displacement of the rear part of the vehicle. The working with is calculated to 605 mm, i.e. W1 or W2.
ROBUST project Page 8 Table 4.1 Drawing/Fe-model. Temporary Vertical Concrete Safety Barrier Table 4.2 FE-model Vehicle restraint system Computer model Model description Nodes Shell/Volume elements Spot welds Materials 24661 4860/19440-3 Table 4.3 Material characteristic. Part E-Module [MPa] Density [kg/m3] Yield Stress [MPa] Ultimate Stress [MPa] Comments Concrete 40000 2500 - - Rigid
ROBUST project Page 9 Table 4.4 Vehicle - Front view. Time 0.00 Time 0.20 Time 0.40 Time 0.60 Time 0.8 Time 1.00
ROBUST project Page 10 Table 4.5 Vehicle - Side view. Time 0.00 Time 0.20 Time 0.40 Time 0.60 Time 0.80 Time 1.00
ROBUST project Page 11 Table 4.6 Vehicle - top view. Time 0.00 Time 0.20 Time 0.40 Time 0.60 Time 0.80 Time 1.00
ROBUST project Page 12 Table 4.7 Vehicle - view. Time 0.00 Time 0.20 Time 0.40 Time 0.60 Time 0.80 Time 1.00
ROBUST project Page 13 Top view Table 4.8 Vehicle damage Bottom view Side view Side view View View
ROBUST project Page 14 5 GENERAL COMMENTS TO THE FE-MODEL This chapter gives general comments to the FE-model based on Force Technology s general knowledge about crash tests and computer simulations of barriers Visual view of the FE-model: The FE-model is similar to trucks on the roads today. Some beam elements extended from the axels are below the roadway. This has probably been done intentionally, and does not affect the results, but the model developer should give an explanation for this modelling approach. Material input: The material input is reasonable. However, some material has been modelled perfect plastic. Some hardening may be implemented. Element formulation: No comments Mesh density: The mesh density is reasonable. The model do not required a lot of CPU time, which is an advantage. Rigid bodies and nodal rigid bodies: The model consists of a large number of rigid materials and nodal rigid bodies. An inspection of the rigid bodies reveals that it is only a small part of the vehicle, which is given rigid material. The mass of the nodal rigid body makes up more than half of the total mass of the FE-model. Search for warnings in the output file: The output-file of FE-model gives some warnings when starting the simulations. These warnings are: Seven spring-materials are defined as a rotational spring, but no orientation vector has been defined. 1152 overlapping shell elements have been detected. Whether the above reported warnings will influence the behaviour of the vehicle, should be evaluated by the model developer.
ROBUST project Page 15 6 CALCULATION OF KINETIC ENERGY AND THEORETICAL AVERAGE FORCE General Annex B in EN1317 gives a theoretical approach of how to calculate average contact force as a function of barrier displacement. The average force with the respect to lateral displacement is expressed as follow: 1 F = S n Sn 0 F( s) ds Using this approach for the simulation performed gives an average force of approximately 130 kn. The contact force versus displacement is shown in Figure 6.1 EN1317 Annex B, states that theoretical and experimental evidence show that the maximum value of the force F(s), is 2.5 times larger than F. Using this statement on the calculated average force gives: F = 2,5 F = 2,5 130kN 325kN max = As figure 6.1 shows, the first force peak is approximately in this force range, but the second peak is above 500 kn. This could indicate that the FE-model behaves somewhat more rigidly than expected. 600 Contact force versus lateral displacement 500 Displacement [mm] 400 300 200 100 0 0 200 400 600 800 1000 1200 Force [kn] Figure 6.1 Contact force versus vehicle lateral displacement
ROBUST project Page 16 7 REFERENCES Ref. 1 Ref. 2 EN 1317-1: Road restraint systems Part 1: Terminology and general criteria for test methods. European Committee for Standardization, April 1998. 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