Research On The Safety Of The Co-driver Side Under Multiple Crash Cases

With the increasing of vehicle population,more and more accidents are happening nowadays,so people have to pay more attention to the safety of occupants.Currently,the research on occupant safety performance mainly focuses on the driver side while the co-driver side is ignored.The research object is mainly about the Hybrid ? 50 th percentile male dummy but the researches on other shapes of occupant are relatively deficient.In different crash types,the two frontal crashes-full frontal crash and offset crash account for the highest proportion,over 50% together.Therefore,it's meaningful to study the safety of the co-driver under frontal crashes.In view of the problems above,the safety of the co-diver under different crash cases is studied and the detailed work is listed as follows:First,the current situation of the traffic safety is summarized and the research status for the co-driver is listed.The national and foreign frontal crash regulations and the injury criteria are also summarized.Then the injury limits of the 95 th percentile male dummy are calculated according to the 50 th percentile male dummy using dummy scaling theory and then the formulas of the weighted injury criterion for the 5th percentile female dummy and the 95 th percentile male dummy are defined.The simulation models of the frontal 100% overlap rigid barrier crash(full frontal crash)and the 40% overlap deformable barrier crash(offset crash)are built,then the real car crash tests are conducted according to the C-NCAP regulation.The simulation models are correlated with the dummy injury curves and the dummy movement.The simulation models for the 5th percentile female dummy and the 95 th percentile male dummy are built based on the two foundation models.So six simulation models for two types of crash and three dummies are built at last.The dummy injury values in these six cases is compared,then the kinematics response and injury risk of different occupant bodies under the same crash are analyzed.The multi-object optimization under six crash cases are carried out to minimize the values of the weighted injury criterion.The NSGA-? algorithm is conducted by using the gamultiobj function contained in MATLAB to achieve the optimization goal.The finial parameter combination is indicated below: when the upper fixed point of the seat belt is 0.8 meters high from the floor,the diameter of the vent hole of the airbag is 50 mm,the load limit of the seat belt is 0.8 times of the original value and the mass flow rate increased to 1.29 times the original value,the overall optimization effect is the best.The values of weighted injury criterion decrease significantly for the dummies in six crash cases,in those cases,the values of weighted injury criterion for the 5th female dummy under two frontal crashes drop by 9.8% and 11.5% separately,the values of weighted injury criterion for the 50 th male dummy decrease by 13.3% and 11.5% accordingly and the values of weighted injury criterion for the 95 th male dummy decrease by 9.1% and 8.0%.The multi-object optimization method of the restraint system could take into account the safety of the occupants of different shape and different crash forms efficiently and the optimization effect is obvious.