Research On The Crash Compatibility For Passenger Vehicle In Front-to-Side Impact

The findings jointly studied by World Health Organization, Public Health School of Harvard University and Bank of World show that:In 2020, traffic accidents will be the third main reason contributed to death and lost labor ability of human, and the number of people will be over 1,400,000 each year. About 30% accidents is side impact which ranked behind frontal impact accident. In the side impact accidents which cause occupants to death and serious injury, the fatality ratio of drive for struck vehicle is several times or even tens than the fatality ratio of drive for striking vehicle. The objective of achieving vehicle safety and crash compatibility is to minimize injury risks for all occupants involved in the side impact collision. Hence, based on the research of lots of references and Federal Motor Vehicle Safety Standard (FMVSS) 214, using the methodologies of induction analysis, numerical analysis, statistic analysis and finite element, respectively studied the lumped parameter model, parameter inverse-solve, injury risks of occupants and deformation vehicle, and parameters influenced crush intrusion of vehicle side structure.1. Investigation of injury epidemiology of crash compatibility for passenger vehicle in front-to-side impact. In this study, NASS/CDS database was used to investigate the distribution of MAIS3+ injured occupants and five main serious injury body regions (including head/face/neck, chest, pelvis, upper extremity and lower extremity) of MAIS3+injured occupants by the overall change in velocity(â–³v) for the striking vehicle and the struck vehicle. And also investigated the distribution of MAIS3+injured occupants and main seriously injured body region of MAIS3+injured occupants by longitude location, horizontal location, and vertical location of damage for the struck vehicle according to the SAE Standard J224. The results indicated that: In LTV-to-CAR side impact collisions in real world, the overall change in velocity (â–³v) contributed to MAIS3+injuried passengers and 50% injury risks is 34km/h and 28.5km/h respectively for striking vehicle and struck vehicle. Finally the protection strategies to improve safety of occupants for the struck vehicle were discussed from different angles.2. Research on the lumped parameter model and parameter inverse-solve method for crash compatibility in front-to-side impact. The lumped parameter models which used by researchers in the past two decades were concluded, and several typical parameter models were described more details. In order to solve the nonlinear rigidity of spring and damping of parameter model, one mathematic methodology was developed, which was entitled parameter inverse-solve method. The method is that using piecewise parameter approximation to fit the test data of side impact conducted by regulations, and combining with nonlinear dynamic system equations, to inverse-solve the dynamic characteristics of absorbed energy components of passenger vehicle and the structure of test dummy in side impact. Comparatively analyzed the results of test method and finite element method, the results was given actually by nonlinear parameter inverse-solve method, could gain the nonlinear responds of vehicle parts and dummy in side impact.3. Qualitative analysis for crash compatibility in passenger vehicle front-to-side impact. Based on the Conversation of Momentum Law, Newton's Law and Moment Theory, combining with a simplified lumped parameter model, and door and SID dummy free-body model, the influence of three primary factors:mass ratio, front-end stiffness and geometry resulting in vehicle incompatibility were analyzed and summarized with three assessment algorithms:Crush-work Stiffness (KW), True Average Height of Force (AHOF), and Partner Protection Assessment of Deformation (PPAD). The research conclusions explored the depth discipline of crash compatibility in front-to-side impact, and implied the study leads for compatibility in front-to-side impact. Meanwhile, described the Finite Element (FE) model of the Progressive Deformable Barrier (PDB) developed by European Enhanced Vehicle-safety Committee (EEVC) and Frontal Impact Working Group (WG15). While the value of PPAD is less, the crash compatibility of the test vehicle is better.4. Simulation study for crash compatibility in passenger vehicle front-to-side impact. Based on Explicit of Finite Element Method, Two Dimension Crash Theory and Penalty Function Method, a series of FE models of passenger vehicle (including Taurus, Explorer, F250 and Silverado) and US-Mobile Derformation Barrier were built and validated according to the rule FMVSS 214. And simulate analyzed followed US New Car Assessment Program Side Impact (US-SINCAP). Fanally the crush intrusion of the position of rail (level 1), middle door (level 3) and window lower part (level 4) for target vehicle was studied. The results indicated that the crush intrusion of level 3 ranked first position, and the crush intrusion of level 1 ranked lastest position for passenger vehicle in front-to-side impact.5. Study on influence factors for crush intrusion in passenger vehicle front-to-side impact. Based on the simulate results, making the side crush intrusion of the Taurus as the objective of research, the relationship among variables was studied when the delta velocity of its side was 28.2km/h. Research variables included the two vehicle weight ratio, primary energy absorbing structure relative position, and approach velocity and contact area of striking vehicle. With the data of statistic analysis accidents of real world, analyzed the influence of crush intrusion on the passenger abbreviate injury scale (AIS) value. The research findings were that:â‘ The main reason contributed to crush intrusion of struck vehicle was the two vehicle weight ratio, when the value was equal to 1.6, the crush intrusion is the least and the value is 402mm, AIS value is 3.23.â‘¡When the relative position of primary absorbing structure for striking vehicle and struck vehicle was changed, the crush intrusion of struck vehicle also would be changed. With the front-end height of striking vehicle became down lower, the crush intrusion of level 3 and leve 4 for struck vehicle would reduce gradually, meanwhile the crush intrusion of level 1 would increase firstly and then decrease.