Simulation Analysis And Rtructural Optimization Of Low-speed Frontal Collision Of Pure Electric SUV Based On RCAR

With the rapid increase of car ownership in China,traffic collision accidents have also increased.A large number of traffic accidents have caused serious casualties and property losses,and have had serious social impacts.Because casualties usually occur in high-speed collision accidents,auto manufacturers and consumers attach great importance to it.Compared with high-speed collision accidents,low-speed collision accidents are less harmful to humans and often lead to the destruction of related parts of the vehicle.Property damage,therefore,low-speed collision and high-speed collision are equally important in car crash safety.In addition,the vigorous development and use of electric vehicles has made cars have different requirements in terms of collision safety.Therefore,research on low-speed collisions of electric vehicles is of great significance to improve the safety and crashworthiness of their collisions,as well as to reduce vehicle maintenance costs and insurance claims caused by collisions.This article uses CATIA software to build a three-dimensional model of a pure electric SUV.According to the two test procedures of the RCAR low-speed frontal collision regulations,the low-speed structure frontal collision of the vehicle at 15km/h and the vehicle at 10.0km/h speed impact 100%full-width bumper collision at a low speed front of the fixed rigid bumper barrier with a height of 455mm±3mm above the ground,the ANSA pre-processing software was used to establish the low-speed frontal collision finite element model and the frontal 100%full-width bumper collision finite element model of the pure electric SUV,and the LS-DYNA solution software was used to simulate the two finite element models.The crash resistance of the pure electric SUV in frontal collision of low-speed structure was analyzed from the deformation of the external structure of the vehicle,the deformation of the internal structure and the deformation of the main energy-absorbing components in the front buffer.It conducts crashworthiness and maintenance economic evaluation;the crashworthiness and maintenance economy of the vehicle in frontal 100%full-width bumper collision were evaluated from the perspective of body deformation and body damage.The problem of insufficient crashworthiness of the front-end structure of the pure electric SUV under two working conditions is comprehensively analyzed.Aiming at the problems existing in the process of low-speed frontal collision,the low-speed structural frontal collision is used as an optimized model.The low-speed collision energy absorption,the plastic strain of the front side member and the deformation of the main energy-absorbing components at the front are used as evaluation indicators.Using the control variable method,and selecting the thickness,material and section type of the front collision beam as optimized parameters to improve the front collision beam to obtain a collision beam structure with the best collision resistance performance;Taking the performance index of the energy absorbing box and the plastic strain of the front side member as the evaluation index,on the premise of improvement of the front side member,four improvement plans for the energy absorbing box are designed,and the energy absorbing box and the front side member are simultaneously improved to obtain low speed Improved energy absorption box with optimal collision performance;After the structure of the front collision beam,energy absorption box and front side member is improved,the compression deformation of the energy absorption box and the plastic deformation of the front side member still exceed the limit.In addition,considering the high strength and resistance Crash and lightweight,a multi-objective optimization scheme for the main energy absorption components of the front buffer zone is designed for secondary optimization,Taking the total energy absorption of the energy absorption box and the anti-collision beam as the maximum,the minimum total mass of the optimized components,the compression distance of the energy absorption box,the maximum value,and the maximum value of the peak force F of the energy absorption box as the objective functions The thickness of the energy box and the front longitudinal beam and the thickness of its reinforcing ribs are design variables.Use the orthogonal test design method provided by Isight software to collect sample points and establish a response surface proxy model,and the second-generation non-dominated sorting genetic algorithm(NSGA-II)is used to find the optimal solution.Compared with the basic model,the optimized final result meets the requirements of the RCAR test,and provides a basis for improving the design and improvement of low-speed collision safety of electric vehicles.