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Informal document No. GRSP-35-9 (35th GRSP, 3-5 May 2004, agenda item A.6.). JMLIT Compatibility Research. GRSP, May 2004 JMLIT. JMLIT Compatibility Research. Development of test procedures Accident analysis Crash tests Cooperation with IHRA
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Informal document No.GRSP-35-9 (35th GRSP, 3-5 May 2004, agenda item A.6.) JMLIT Compatibility Research GRSP, May 2004 JMLIT
JMLIT Compatibility Research • Development of test procedures • Accident analysis • Crash tests • Cooperation with IHRA • The research are conducted in JMLIT Compatibility WG
Vehicle Fleet in Japan 12,000 Small car 10,000 Minicar Large car 8,000 Vehicle registrations (*1000) MPV 6,000 Medium car 4,000 Wagon SUV 2,000 0 1992 1993 1994 1995 1996 1997 1998 1999 2000 Year
Key Factors of Compatibility • Structural interaction • Force matching • Compartment strength
Full-Width Crash Tests • Full-width rigid barrier crash tests have already been in the regulations of Japan, US and Australia as a high-acceleration test for restraint systems. • Barrier force distributions are measured for structural interaction evaluation. • Full-width tests are agreed as phase I in IHRA compatibility WG.
Full-Width Tests in Japan • 125 x 125 mm load cells • 44 rigid barrier tests (42 JNCAP + 2 additional tests) • 6 (TRL) deformable barrier tests Rigid barrier Rigid barrier Deformable barrier
50- 45-50 40-45 35-40 30-35 25-30 20-25 15-20 10-15 5-10 0-5 unit : kN Force Distributions in Full-Width Rigid Barrier Tests Nissan Liberty AHOF: 434 mm Honda Accord AHOF: 410 mm AHOF=average height of force F Fi = H(t) Honda Stepwgn AHOF: 487 mm
Car-to-MPV - Similar AHOF - Nissan Liberty AHOF: 434 mm Kerb mass: 1516 kg Honda Accord AHOF: 410 mm Kerb mass: 1441 kg 5 mm AHOF difference is 24 mm
Car-to-MPV - Different AHOF - Honda Accord AHOF: 410mm Kerb mass: 1440 kg Honda Stepwgn AHOF: 487 mm Kerb mass: 1528 kg 45 mm AHOF difference is 77 mm AHOF can be an effective parameter to predict override/underride in car-to-car crashes.
80 60 40 20 0 16 S1 15 14 13 S3 12 11 10 9 S5 8 7 6 S7 5 4 3 2 1 Full-Width Deformable Barrier Tests • Structural forces are seen clearly without engine footprint. • Forces from lower cross member can be seen? • Relative homogeneity assessment has been proposed in deformable barrier tests. Relative Homogeneity Assessment Variability of peak load (Individual cells, each row and each column) Excite shear deformation like car-to-car crashes 1.6 1.4 Columns 0.32 Rows 1.2 Cells 0.30 1.0 0.8 Force (kN) 0.20 0.6 0.07 0.10 0.90 0.13 0.18 0.06 0.4 0.05 0.09 0.15 0.14 0.45 0.2 0.32 0.28 0.24 0.21 0.0 Force from lower cross member or force dispersion by honeycomb? Wagon R Vitz Legacy Forester STEPWGN SURF
50- 45-50 40-45 35-40 30-35 25-30 20-25 15-20 10-15 5-10 0-5 unit : kN Force Distributions by Load Cell Alignment Load cell Ground height 125 mm Ground height 50 mm 125 mm Ground level 50 mm Target load = 7.1 kN Target load = 6.8 kN Relative homogeneity assessment 30 30 Londitudinal impact load cell 20 0.6 20 0.5 0.4 10 Columns 10 0.3 Rows Cells 0.2 0 16 0 15 S1 0.1 14 16 S2 13 15 S1 12 S3 14 11 S2 13 10 0 S4 12 9 S3 11 8 S5 10 S4 7 9 S6 125 mm 50 mm 6 8 S5 5 S7 7 4 S6 6 3 S8 5 S7 2 Load cell ground height 4 1 3 S8 2 1
Unrealistic Deformation by Deformable Barrier Car structures Deformable barrier test Car-to-car test Satellite sensor Large cross-section of front-end, which will be useful for structural interaction, can be disadvantageous in full-width deformable barrier tests.
Injury Criteria of Driver Dummy in Full-Width Rigid and Deformable Barrier Tests Minicar Small car Medium car • Injury criteria are comparable between rigid and deformable barrier tests. • Due to crash sensing time differences, injury criteria in deformable barrier tests can be higher than rigid barrier tests, especially for high-acceleration cars. HIC HIC HIC Chest acc Chest acc Chest acc Chest deflection Chest deflection Chest deflection Femur right Femur right Femur right Rigid barrier Deformable barrier Femur left Femur left Femur left 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Small SUV SUV HIC HIC Chest acc Chest acc Chest deflection Chest deflection Femur right Femur right Femur left Femur left 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Injury criteria/IARV Injury criteria/IARV
AHOF in Full-Width Rigid and Deformable Barrier Tests 550 500 AHOF in TRL barrier tests (mm) 450 400 400 450 500 550 AHOF in rigid barrier tests (mm)
Full-Width Deformable Barrier Tests • Forces from structures can be seen clearly. • It is still not clear if the foot print of cross members can be seen in deformable barrier tests. • AHOF is comparable between rigid and deformable barrier. • Load cell alignments affect force distribution measurements and relative homogeneity assessments. • Unrealistic deformation can occur. • Deformable barrier tests can be used as high deceleration tests for restraint system evaluation.
Full-Width Tests for Structural Interaction Evaluation • AHOF is a useful criterion to evaluate underride/override. • To determine the AHOF, the force distributions measured in either rigid or deformable barrier tests can be used. • Further research is necessary for deformable barrier and homogeneity assessment criteria.
Car-to-Car Tests (50 km/h) Vitz(Echo) 2001 Australia test Vitz 2003
Overload Tests (80 km/h) 2002 Vitz 2003 Vitz
Compartment Strength Criteria • Maximum structural force • End of crash force Barrier force at the time when the difference between engine inertia force and barrier force is maximal • Rebound force Barrier force at the time when car starts to rebound End of crash force Barrier force Rebound force Engine inertial force Displacement
Overload and Car-to-Car Tests 300 Civic 1999 (vs. Crown) 250 vs. Crown (55 km/h) Wagon R 2001 (vs. Crown) 200 Firewall intrusion of small car in a crash into a large car (mm) Move 2000 (vs. Crown) 150 Vitz 2000 (vs. Legacy) vs. Legacy (50 km/h) 100 Vitz 2003 (vs. Legacy) 50 0 0 50 100 150 200 250 Rebound force in overload tests (kN)
Rebound Force in 80 and 64 km/h Tests 250 Move 2000 200 Vitz 2003 150 Wagon R 2001 Rebound force in ODB 64 km/h tests (kN) Civic 1997 100 Vitz 2002 50 0 0 50 100 150 200 250 Rebound force in overload 80 km/h tests (kN)
Summary – Compartment Strength • It was demonstrated that a strong compartment is effective in improving the self-protection. • Overload tests are useful for predicting the compartment strength. • Some criteria have been examined to evaluate the compartment strength. • Compartment strength may be evaluated in ODB 64 km/h tests.
JMLIT Compatibility Research Report for IHRA Compatibility WG