Dynamic Response of the THOR-NT: Thorax and Abdomen

Transcription

1 Dynamic Response of the THOR-NT: Thorax and Abdomen MitsutoshiMasuda, Toyota Motor Corporation Sabine Compigne, Toyota Motor Europe 1

2 Background Distribution of AIS3+ injuries by body region and vs. seating position 50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Nb injuries/nb casualties Driver Front Passengers Rear Passengers Head Chest Abdomen Spine Upper Ext. Pelvis Lower Ext. Martin et. al, 2010: Car occupants with AIS 3+ injury, N=1219 (French data-rhône Road Trauma Registry) 2

3 Thorax injuries: Specificities of elderly car occupants % MAIS 3+ casulaties Elderly females Young females Elderly males Young males AIS0 AIS1 AIS2 AIS3 AIS4 AIS5 AIS6 Thorax AIS among MAIS3+ belted casualties, N=723 Elderly people (>60 YO) vs Young people (20-34 YO) (French data-rhône Road Trauma Registry ) Ifsttar-Toyota report,

4 Thorax injuries: Specificities of elderly car occupants 75+yrs Steering Wheel Belt restraint webbing/buckle 65-75yrs 45-64yrs Instrument panel and below Center instrument panel and below Interior surface, excluding hardware or armrests Seat,back support 25-44yrs Airbag Other/Unknown 0% 20% 40% 60% 80% 100% NHTSA TR DOT HS : AIS2+ distribution of sources of thoracic injuries in frontal crashes (NASS-CDS ) 4

5 Thorax injuries: Specificities of elderly car occupants Rib w/wo hemo/pneumothorax Flail chest Internal organs/vessels Whole area (crush) Rib Sternum Internal organs/vessels & others Elderly males Old men Elderly females Old women Young males Young men Young females Young women % 20% 40% 60% 80% 100% Distribution of different AIS3+ thoracic injuries, N=377 Elderly people (>60 YO) vs Young people (20-34 YO) (French data-rhône Road Trauma Registry ) Ifsttar-Toyota report, 2009 NHTSA TR DOT HS : Distribution of different AIS2+ thoracic injuries in frontal crashes (NASS-CDS ) 5

6 Thorax injuries: Rib fracture patterns Frequent lower rib fractures at buckle side w/ab Importance to assess this phenomenon to improve restraint systems w/ab wo/ab w/upper rib fractures 4 2 w/lower rib fractures 7 1 Crush Total Shimamura et al. (2003): Injuries to chest and fracture locations of belted occupants in frontal crashes(itarda data, ) 6

7 Consequences for ATD chest Higher priority for elderly Assessment of injury risk for skeleton parts Assessment of injury risk under seat belt loading Asymmetrical loading Multi-points measurement Assessment of injury risk under steering wheel 7

8 THOR thorax geometry vs. human & HIII A humanlike rib cage geometry Allows a more realistic steering wheel lower rim contact with the lower rib cage Human THOR-NT Hybrid III Shaw et al., 2007: SAE THOR workshop 8

9 THOR thorax response vs. THUMS & HIII THOR simulates THUMS rib cage asymmetrical deformation The 4-point measurements can quantify the asymmetry to discriminate restraint systems THUMS ver.3 Hybrid III Thorax deformation pattern of human surrogates under belt loading 9 Thorax deflection of belted THOR-NT in 56 km/h sled test UR LR Thorax Deflection (mm) Deflection(mm) UL LL Chest Disp-x(mm) Chest Stroke(mm) LL UR UL LR

10 Abdomen injuries: Specificities of rear occupants Significant OR in yellow Significant OR in yellow Head Chest Abdomen Spine Upper Ext. Pelvis Lower Ext. 0 Head Chest Abdomen Spine Upper Ext. Martin et al., 2010: Relative risk of AIS3+ per body region for rear passengers vs.drivers (left) and FSP (right) -OR and 95% CI (French data-rhône Road Trauma Registry ) Pelvis Lower Ext. Drivers (N=64) FSP (N=35) RSP (N=16) AIS 2+ solid organ injuries 65% 69% 37.5% AIS 2+ hollow organs injuries 35% 31% 62.5% Lamielleet al., 2006: AIS2+ solid and hollow organ injury distribution by occupant position 10

11 Current ATDs abdomen HIII Abdomen not instrumented JNCAP (2009) Belt slipping above the pelvis iliac crests: YES/NO THOR-NT Abdomen instrumented BUT Limited biofidelity Localized measurements 11

12 Proposal for a new THOR abdomen Collaborative project with Ifsttar(France) François Bermond, Gaëtan Hanen Development tasks ACCIDENT DATA > MAIN INJURY SOURCES > MAIN INJURY PATTERNS EVALUATION OF EXISTING CONCEPTS PROTOTYPES 1 IMPROVEMENTS: PROTOTYPE 2 DESIGN BRIEF LITTERATURE REVIEW > EXISTING CONCEPTS > INJURY CRITERIA Toyota/GESAC prototype THOR-NT lower abdomen Based on THOR-NT THOR-FT lower abdomen (uninstrumented) 12 HIII silicone abdomen (Rouhana, 2001)

13 Abdomen response evaluation Rigid-bar impacts Certification test for THOR lower abdomen 3 and 6.1 m/s Seat belt loading Based on Foster et al. (2006) Pretensioner System C 5 m/s Pretensioner System B 9.5 m/s Pretensioner System A (=2 B ) 16.5 m/s Rigid bar impact test set-up Seat belt test set-up (Foster, 2006) 13

14 Responses comparison: Rigid bar impact at 6.1 m/s Force (N) PMHS Corridor (Cavanaugh) Toyota/GESAC (Hardy) THOR-FT THOR-NT Silicone abdomen (Rouhana) Penetration (mm) 14

15 Responses comparison: Seat belt System B PMHS Corridor (Foster) Toyota/GESAC THOR-FT THOR-NT Silicone abdomen (Rouhana) Force (N) Penetration (mm) 15

16 Prototype #1 Pressure sensors into THOR-NT lower abdomen Upper abdomen partially removed Prototype #1 THOR-NT (no jacket) 16

17 Prototype #1 biofidelity: Rigid bar impacts at 6.1 m/s 12 Prototype #1 10 THOR-NT Force (kn) Penetration (m) 17

18 Prototype #1 biofidelity: Seat belt System B 8 Prototype #1 7 THOR-NT 6 Force (N) Penetration (m) 18

19 Prototype #1 pressure sensor responses: Rigid bar impacts Good repeatability 3 Pressure (bar) m/s 3 m/s Time (s) Identical response of R&L sensors under symmetrical loading 19

20 Prototype #1 pressure sensor responses: Seat belt Good repeatability Identical response of R&L sensors under symmetrical loading Pressure peaks proportional to retraction speed Pressure (bar) System A System B System C Time (s) 20

21 Prototype #2 Simulations performed in parallel to guide design modifications Force (kn) Improve abdomen biofidelity(tests) Biofidelity corridor THOR-NT Prototype #1 THOR-NT abdomen with added masses THOR-NT FE Model providedby UVa& NHTSA/USDOT withoct update from JARI/JAMA Penetration (m) 21

22 Prototype #2 Modified pressure sensor geometry to fit THOR lower abdomen space Completion end of March 2012 Sled tests planned at Toyota Motor Corporation from April

23 Conclusions THOR-NT is a suitable tool to assess chest injury risk THOR-NT with abdomen prototype #2 can assess abdominal injury risk: In OOP seat belt type tests To be confirmed in crash configurations 23

24 We would like to acknowledge & JAMA/JARI for their contribution to these studies 24