Effectiveness of SEAS in Car-to-Car Frontal Crashes JAPAN 19th Meeting of the Informal Group on Frontal Impact 1

Objective To examine the effectiveness of SEAS in frontal impact between vehicles with a vertical mismatch of PEAS 2

3 Test Procedure Stage 1: FWRB test Stage 2: Option 2 test F> mm F3+F4 [100-LR] kN F4 35 kN F3 35 kN LR = Min [(F2+F1-25 kN); 35 LCW force 200 kN Pass No Pass No Fail Yes

Test Condition 50 km/h Full Frontal Car-to-Car Tests Small car SUV 50 km/h Test 1: Original height (front rails of SUV were higher than that of small car) Test 2: Adjusted height (height of front rails of SUV was aligned with that of small car) Small car SUV Small car lowered SUV 4

Test Vehicles Front structures: Front rails, bumper cross beam and SEAS Test mass: 1380 kg Front structures: Front rails and bumper cross beam Test mass: 1138 kg Small car SUV (with SEAS) SEAS Front railsBumper cross beam Front rails Bumper cross beam 5

Test Vehicle - Small car - 6 US voluntary agreement Ground height (mm) (20 in.) 406 (16 in.) PEAS(Front rail)

Test Vehicle - SUV - FIMCAR proposal 7 US voluntary agreement Metric for FWRB test F3+F4 [100-LR] kN F4 35 kN F3 35 kN-LR LR = Min [(F2+F1-25 kN); 35 kN] 55 km/h (JNCAP) MetricRequirement F3+F4 [kN]( 100-LR)118.2 F4 [kN] ( 35) F3 [kN]( 35-LR) 5.4FAIL F2 [kN]21.6 F1 [kN]1.0 LR (Limit Reduction) [kN]0.0 Result MetricRequirement Option 1a [%] a/b ( 50) 2.0FAIL Option 1b [%] a/c ( 50) 2.1FAIL Result Ground height (mm) (20 in.) SEAS 406 (16 in.) PEAS(Front rail)

8 Pre-test Post-test Test Vehicle - SUV - US voluntary agreement Option 2 (Quasi-static test) Photo No. 4 Part [mm] Ground SEAS PEAS FR Tire - Vertical plane at the forward-most point of the significant structure of the vehicle

Geometric Condition Test 1: Original heightTest 2: Adjusted height mm Small car SUV Small car SUV mm Longitudinal distance between front end of bumper cross beam and front end of SEAS for SUV: 248 mm Vertical overlap of front rails between two vehicles in Test 1: 16 mm For SUV in Test 2, not only the front rails but also the engine was lowered. 9

10 Test Videos

Vehicle Behavior 0 ms 30 ms 60 ms Small car SUV Test 1: Original height Test 2: Adjusted height Overriding/underriding did not occur in both tests. The tire is in contact with the road surface (= not overriding).

Velocity Time History Test 1: Original height Test 2: Adjusted height 55.5 km/h 12 The severity for the small car in the two tests is equivalent to 55 km/h km/h 55.5 km/h 45.7 km/h

Vehicle Deformation Test 1: Original height Small car SUV Front rails passed each other. SEAS of SUV engaged the front structures of the small car. 13

Vehicle Deformation Small car SUV Front rails contacted each other. 14 Test 2: Adjusted height

Deformation - Small car - Test 1: Original height Test 2: Adjusted height 15

Deformation - SUV - Test 1: Original height Test 2: Adjusted height 16 The contact with the front structure of the small car caused a significant deformation of SEAS in Test 1.

Injury Measures - Small car - Passenger's dummy 17 Injury levels were comparable between Test 1 (original height) and Test 2(adjusted height). Driver's dummy HIC 36 Neck Fz Neck Fx Neck My Chest Deflection Chest G-3 ms Femur Force Tibia Index Ratio of injury measures to IARV (%) Driver's Dummy 50 km/h CTC Org Height 50km/h CTC Adj. Height 55 km/h FWRB

Injury Measures - SUV - Passenger's dummy 18 Injury levels were comparable between Test 1 (original height) and Test 2(adjusted height). Driver's dummy HIC 36 Neck Fz Neck Fx Neck My Chest Deflection Chest G-3 ms Femur Force Tibia Index Ratio of injury measures to IARV (%) Driver's Dummy 50 km/h CTC Orig. Height 50 km/h CTC Adj. Height 55 km/h FWRB

Conclusions In the SUV-to-small car test with vertical mismatch of PEAS, the SUV did not override the small car because the SEAS of the SUV engaged the front structures of the small car. Injury levels for the driver and passenger dummies in the small car were comparable between the two tests. From the two tests, it was shown that SEAS is an important structure for structural interaction between vehicles. Therefore, when a test procedure on structural interaction is developed, it is necessary to consider an evaluation of not only PEAS but also SEAS. 19

Appendix

Vehicle Acceleration Small car SUV Right B-pillar 21

Dummy Response - Small car - Head resultant acc. (m/s 2 )Neck extension moment (Nm) Chest deflection (mm)Femur-R force (kN) Driver 22

Dummy Response - SUV- Head resultant acc. (m/s 2 )Neck extension moment (Nm) Chest deflection (mm)Femur-R force (kN) Driver 23

Test 1: Original height Engine Behavior Small car 24 Test 2: Adjusted height Small car SUV Small car SUV Small car SUV Small car SUV pre-test post-test pre-test post-test