Simulation And Optimization Design Of Frontal 25% Vehicle Small Overlap Crash

With the continuous increase of car ownership,due to the frequent traffic accidents caused by improper driving and other cars,causing a lot of losses to the society,and also brought certain safety problems to passengers and pedestrians,the safety of car collision has been paid attention to.Compared with other collision forms,frontal 25% small bias collisions have a high probability and greater damage.In 2012,IIHS(Insurance Institute for Highway Safety)issued the positive 25% small overlap test specification,and most of the test vehicles were poor.In 2017,the positive 25% small overlap test specification was released in China,and the evaluation rating of each model attracted attention.Therefore,according to the safety requirements of automobile collision,this paper evaluates the vehicle structure of the frontal 25% small overlap collision,and optimizes the vehicle structure through the automobile collision resistance multi-objective optimization method,which is of great engineering significance for the collision safety design.According to the 2020 version of China insurance automobile safety index evaluation procedures of positive small bias collision test method and evaluation procedures,build a car collision finite element model,and the positive 25% small bias collision simulation calculation,the vehicle energy,vehicle deformation,vehicle collision force transfer path,crew cabin structure deformation,vehicle local location intrusion,speed and acceleration are analyzed.The plate thickness was selected as the optimization variable,the optimization design variable was determined by sensitivity analysis,and a proxy model with the amount of hinge intrusion on column A,hinge intrusion under column A and threshold beam intrusion was constructed,optimized by NSGA-II algorithm.Finally,the optimized results are evaluated to safety analysis and rating,and the impact of the optimized structure on100% collision performance is analyzed.The correct model establishment and simulation analysis results provide the basis for the vehicle crash resistance optimization.The analysis of the influence of important plate thickness by constructing an agent model shows that the thickness of single plate and multiple plate thickness are different,and the simultaneous change of multiple plate thickness has more impact on the intrusion volume.The optimization algorithm reduces the amount of 10.5mm and 19.6mm.The grade is conducted according to the positive 25% small bias evaluation procedure,and the optimized result level is higher than the result level before optimization.Bring the optimized plate thickness into the 100% frontal collision model and reduce the intrusion volume of the important components by 5% to 8%.This study achieves a multi-objective optimization goal.