Study On Frontal Crash Passive Safety For Sedan Car

Automotive safety issues have been accompanied by the development of automobileindustry, and have been the focus of governments, society and major manufacturers. Toprotect persons in traffic accidents and enhance the vehicle's passive safety, governments andorganizations have developed rigorous safety regulations and protocols, which are not onlythe basis for testing and evaluating automotive passive safety, but also specify the direction ofpassive safety design. Frontal crash is a major impact mode in real traffic accident and passivesafety regulation, so the frontal crashworthiness is one of the essential design targets forvehicle passive safety. In addition, pedestrian protection has gotten more and more concernsof governments, manufacturers and society, considering pedestrian protection in the design offront structure has become a new trend for frontal passive safety design. On the basis offrontal passive safety development, the frontal structure crashworthiness design, occupantrestraint system matching and pedestrian lower leg protection were studied in-depth. Thecontent in this paper are as follows:â‘ On the basis of the vehicle-occupant kinetic model, The intrinsic relationship andinfluence of occupant restraint system parameters on the occupants injuries were analyzed.Using MATLAB software, sensitivity analysis of occupant injury response on the accelerationlevel, the maximum dynamic deformation, natural frequency and slack of restraint systemwere discussed.â‘¡According to the vehicle-occupant mathematic model, sensitivity analysis of dummyinjuries on the two stage acceleration characteristic parameters were analyzed, then themethod was applied to define the front crashworthiness objective in practice. In view of theenergy management, the method of vehicle frontal structure optimization was proposed basedon average crushing force sustained by main energy-absorbing component in frontal crash,which was successfully applied on the frontal structure crashworthiness optimization of adomestic sedan and validated by full vehicle impact test. At the same time, improvements forthe intrusion of the compartment in the mode of64km/h40%Offset Deformable Barrierimpact was fulfilled then were also validated effective by full vehicle impact test.â‘¢To mount other vehicle frontal airbags and seat belts in the vehicle used to verify thefrontal structure crashworthiness in a domestic sedan passive safety development process,which reduced the number and scope of parameters for the restraint system optimization. Thesimulation model of occupant restraint system was created, which validated by componenttest and sled test. Two step DOE method was created to optimize occupant restraint systemand validation tests were fulfilled. A domestic sedan adult occupant protection was evaluated based on the C-NCAP (2010) and the Euro-NCAP (2012).â‘£The affects of the front of the shape, spatial arrangement, the front-end structuralparameters and stiffness characteristics on the pedestrian lower leg protection were discussedin details. Combined with the passive safety development of a domestic sedan, applyingmulti-rigid body and finite element coupling calculation improved the pedestrian lower legprotection performance.The innovations in this paper are as followsâ‘ The method of vehicle frontal structure optimization was proposed based on averagecrushing force sustained by main energy-absorbing components in frontal crash, which couldimprove efficiency and accuracy of the frontal structure crashworthiness simulation.â‘¡To mount other vehicle frontal airbags and seat belts in the vehicle used to verify thefrontal structure crashworthiness in a domestic sedan passive safety development process,which reduced the number and scope of parameters for the restraint system simulation.â‘¢Two step DOE method was created to optimize occupant restraint system, whichenhanced the accuracy and control of optimization.â‘£Multi-rigid body and finite element coupling calculation method was created toimprove the pedestrian lower leg protection.The research project covered in the paper was a domestic self-developed platform aimedat Euro-NCAP (2012)5-star rating for the first time. Through the development process ofpassive safety, the general control method of front structure design, restraint system matchingand pedestrian lower leg protection were initially formed to meet the Euro-NCAP (2012),which provided a feasible thesis basis and control methods for car passive safety. Theachievements in the paper had some theoretical and practical significance for self-brandvehicles to get Euro-NCAP5-star rating.