Finite Element Analysis of Passenger Multiple Belt Restraint Configurations by Mao Yu A thesis submitted to the Graduate Faculty of WAKE FOREST UNIVERSITY SCHOOL OF BIOMEDICAL ENGINEERING & SCIENCES In Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE Biomedical Engineering August 2010 Winston-Salem, North Carolina Approved by: Joel D. Stitzel, PhD, Advisor, Chair Examining Committee: H. Clay Gabler, PhD Warren N. Hardy, PhD Acknowledgements Thanks to my advisor Dr. Stitzel and my committee for their patience in me and my lab mates for their assistance. i Contents Acknowledgements i Contents ii List of Figures v List of Tables x Acronyms xi Physical Constants xii Symbols xiii Abstract xiv 1 Introduction and Objectives 1 1.1 Motivation . .1 1.2 Human volunteers, PMHS, animals, and ATDs . .2 1.3 Computer Simulations . .3 1.4 Injury Measures . .4 1.5 Injury Risk Functions . .5 1.6 Safety Equipment . .6 1.7 Study Objective . .7 2 Finite Element Simulation of Frontal Crash using THUMS 8 2.1 Introduction . .8 2.2 Model Structure and Development . 10 2.2.1 Vehicle Interior . 10 2.2.2 THUMS model . 11 2.2.3 Restraints . 12 2.2.4 Boundary Condition . 14 2.2.5 Contact Definition . 15 2.3 Model Review . 18 ii Contents iii 2.3.1 Static Checks . 18 2.3.2 Preliminary Runs . 19 2.4 Results . 22 2.4.1 Simulation snapshots . 22 2.4.2 Overall fringe plots . 24 2.4.3 Skeletal fringe plots . 26 2.5 Discussion . 28 2.5.1 Model development . 28 2.5.2 Post Mortem Human Subject (PMHS) validation . 30 2.5.3 Simulation results . 35 2.6 Conclusion . 38 3 Development of Finite Element Injury Measures for THUMS 39 3.1 Introduction . 39 3.2 Methods . 41 3.2.1 Head Measure . 42 3.2.2 Neck Measure . 46 3.2.3 Chest Measures . 49 3.2.4 Abdominal Measures . 56 3.2.5 Vehicle Interior Measures . 58 3.2.6 Test scenario . 59 3.3 Results . 59 3.3.1 Head . 60 3.3.2 Neck . 72 3.3.3 Chest . 86 3.3.4 Abdomen . 101 3.3.5 Derived measures . 111 3.4 Discussion . 112 3.4.1 Results . 112 3.4.2 Injury measures . 114 3.5 Conclusion . 118 4 Injury Risk Functions for THUMS 119 4.1 Introduction . 119 4.2 Methods . 124 4.3 Results . 131 4.4 Discussion . 137 4.5 Conclusion . 140 5 Comparison of different load limits using Total HUman Model for Safety (THUMS) 141 5.1 Introduction . 141 5.2 Methods . 143 5.3 Results . 149 5.3.1 Simulation snapshots . 149 Contents iv 5.3.2 Head injury measures . 153 5.3.3 Neck injury measures . 155 5.3.4 Chest injury measures . 157 5.3.5 Pelvis injury measures . 162 5.3.6 Risks . 168 5.4 Discussion . 174 5.5 Conclusion . 175 6 Comparison of different pretensioner placement using THUMS 176 6.1 Introduction . 176 6.2 Methods . 178 6.3 Results . 182 6.3.1 Simulation snapshots . 182 6.3.2 Head injury measures . 188 6.3.3 Neck injury measures . 191 6.3.4 Chest injury measures . 193 6.3.5 Pelvis injury measures . 196 6.3.6 Risks . 200 6.4 Discussion . 206 6.5 Conclusion . 208 7 Comparison of four-point and three-point restraint using THUMS 209 7.1 Introduction . 209 7.2 Methods . 210 7.3 Results . 214 7.3.1 Simulation snapshots . 214 7.3.2 Head injury measures . 221 7.3.3 Neck injury measures . 224 7.3.4 Chest injury measures . 226 7.3.5 Pelvis injury measures . 231 7.3.6 Risks . 237 7.4 Discussion . 243 7.5 Conclusion . 245 Bibliography 246 List of Figures 2.1 Vehicle Interior Components . 10 2.2 FE surrogate models . 12 2.3 THUMS chest cavity . 13 2.4 Three-point restraint . 14 2.5 Crash Pulse . 15 2.6 Crash Pulse (Velocity) . 15 2.7 Contact definitions . 17 2.8 Viscus properties . 19 2.9 THUMS simulation snapshot . 23 2.10 Hybrid III (HIII) simulation snapshot . 23 2.11 THUMS fringe plot . 24 2.12 HIII fringe plot . 25 2.13 THUMS fringe plot skeleton . 26 2.14 HIII fringe plot skeleton . 27 2.15 PMHS diagram . 31 2.16 PMHS test pulse . 31 2.17 PMHS validation . ..