Whiplash Prevention the Role of Rating and EuroNCAP

Transcription

1 Whiplash Prevention the Role of Rating and EuroNCAP Dr. Ing. Wilfried Klanner ADAC Technik Zentrum Seminar on Whiplash Injuries City Conference Center (Norra Latin) Stockholm, 28 June

2 Content 1. Accident Statistics, Rear Impact Scenario 2. EuroNCAP Actions 3. Euro NCAP Rear Impact Test Set Up and Pulses 4. Euro NCAP Rear Impact Test Criteria and Rating 5. Time and Working Schedule for Implementation of Rear Impact into EuroNCAP Testing and Assessment Protocol 2

3 Fig. 13 Injury Frequency and Economic Damage Due to Rear Impacts Year 2000 in Germany: accidents with injured occupants Frequency rear impacts and other impacts with injured occupants Annual economic damage due to whiplash injuries: Germany: 1Mrd. Europe: 10 Mrd. North America: 10 Mrd. 51% rear impacts 49% other impacts Most rear impact injuries are whiplash injuries Quelle: Dr. Wolfram Hell, München, Institut für Fahrzeugicherheit (IFM) Most whiplash injuries occur in small cars! 3

4 Seat instability Rear Impact with EES 18km/h Driver mass = 130kg Spine distorsion due to seat instability (ADAC Air Rescue Accident research) 4

5 Whiplah Test with 16 km/h Mercedes A (ab März 2005) VW Polo (ab Januar 2005) + (good) (former model reached -) Θ (sufficient) (former model reached -) 5

6 Seat Stability test with 30 km/h MCC Smart Fiat Punto ++ (very good) - (poor) 6

7 Content 1. Accident Statistics, Rear Impact Scenario 2. EuroNCAP Actions 3. Euro NCAP Rear Impact Test Set Up and Pulses 4. Euro NCAP Rear Impact Test Criteria and Rating 5. Time and Working Schedule for Implementation of Rear Impact into EuroNCAP Testing and Assessment Protocol 7

8 Fig. 4 The Structure of EuroNCAP High Level Liaison Meeting 8

9 2 Choices for basic approach: 1. Protocol based on good understanding of injury mechanisms sufficient information will not be available in the medium term 2. Protocol acknowledging lack of information about injury mechanisms, but encouraging seat design towards current best practice Recommended on basis of extensive work by SRA, ADAC, IIWPG and ACEA (Insurance data suggests around 50% reduction in reported whiplash injury associated with best practice ) EuroNCAP Decision: Choice 2 9

10 Concepts that are encouraged Early head to head restraint contact Low neck loads Energy absorption within system Occupant containment 10

11 Concepts that are discouraged Front occupant moving into the rear occupant s survival space Partial or complete Ejection or excessive ramping up seat back Unrealistic dummy loading Concentrated loads on the occupant Harmful loading to other body areas 11

12 Content 1. Accident Statistics, Rear Impact Scenario 2. EuroNCAP Actions 3. Euro NCAP Rear Impact Test Set Up and Pulses 4. Euro NCAP Rear Impact Test Criteria and Rating 5. Time and Working Schedule for Implementation of Rear Impact into EuroNCAP Testing and Assessment Protocol 12

13 Acceleration (g) Generic Pulses for Whiplash and Seat Stability Testing Time (ms) 30 km/h, ADAC 24m/h,SNRA 16km/h, IIWPG Test set up and pulses 1. Low whiplash pulse 10km/h?, (under consideration)? 16 km/h, 4.5g plateau, 3g mean, (SRA)? 2. Medium whiplash pulse 16 km/h, 10g max, 5.5g mean, (IIWPG, SRA, ADAC) 3. High whiplash pulse 24 km/h, 7g plateau, 6.5g mean (SRA)? km/h seat stability pulse (ADAC)? 5. BioRID dummy 6. Additional incentives 13 for geometry, locking

14 Content 1. Accident Statistics, Rear Impact Scenario 2. EuroNCAP Actions 3. Euro NCAP Rear Impact Test Set Up and Pulses 4. Euro NCAP Rear Impact Test Criteria and Rating 5. Time and Working Schedule for Implementation of Rear Impact into EuroNCAP Testing and Assessment Protocol 14

15 Assessment Criteria for Whiplash and Seat Stability Whiplash Criteria Lower Upper (16 km/h and 24 km/h pulse) Limit Limit NIC NKM 0,20 0,5 Head Rebound velocity [m/s] 4,5 6 Fx upper [N] 130(150) 300(260) Fz upper [N] 600(775) 800(1175) T1g [m/s 2 ] (up to head contact HRC) 9(9,5) 12 HRC [ms] Rel. Mov. Head/Thorax neck shear force & momentum rebound energy neck shear force neck tension force thorax acceleration head to head rest contact time Seat Stability Criteria (30 km/h pulse) Dynamic Back Rest Angle 25 o 40 o Seat deformation 15

16 NIC calculation t [ ] T0,THRC Channels needed: Head T1 γ x, γ x Convert from g to m/s² Filter at CFC 180 (Butterworth) Calculate relative acceleration γ rel x = γ T1 x γ Head x Calculate relative velocity V rel x (t) = t 0 γ rel x ( τ) dτ Calculate NIC NIC (t) = 0.2* γ + rel ( V (t ) 2 rel x (t) x ) Calculate NICmax NICmax = Max NIC(t) t [ T0,THRC] [ ] 16

17 Rating system concepts Sliding scales and equal weights for all criteria Points to be added to occupant protection rating Potential additional points for best seats should open up next star band to give whiplash protection suitable emphasis Modifiers used to encourage good HR height and stability 17

18 Content 1. Accident Statistics, Rear Impact Scenario 2. EuroNCAP Actions 3. Euro NCAP Rear Impact Test Set Up and Pulses 4. Euro NCAP Rear Impact Test Criteria and Rating 5. Time and Working Schedule for Implementation of Rear Impact into EuroNCAP Testing and Assessment Protocol 18

19 Work in short term (Before end July) Produce protocol for communication to industry Check durability and repeatability of dummy at high severity pulse Repeatability and reproducibility of 16 km/h pulse Refine set up repeatability and reproducibility for dummy OSCAR, HRMD Check sliding scale limits against experience with all seat testing so far 19

20 Work within 2005 Explore relationship between seat stability testing and accident experience to provide background for decision Check use of Hybrid III 95%ile or another sized dummy in this context 20

21 Conclusion Whiplash injuries are the most frequent and most cost effective injuries due to traffic accidents As a significant contribution to mitigate this problem EuroNCAP will implement whiplash injury testing and rating as soon as possible, today s time horizon is assumed to be end of

22 Conclusion EuroNCAP allready has made the majority of all decisions necessary, such as dummy, pulse shapes, testing set up, etc But there are still some outstanding problems to be resolved, such as - reproducability between the test labs - several details of rating procedure - importance of seat stability testing in real life accidents Whiplash assessment implementation will open the six star band for excellent performing car models 22

23 Thank you for your attention 23