Analysis And Optimization Of The Low-Speed Impact Performance Of The Automobile Front Bumper

Low-speed collision of vehicles refers to collision accidents with a speed of less than 16km/h.In the low-speed collision,the front bumper is the main load-absorbing component,and its collision performance is directly related to the protection of important components on the front end of the car.On the other hand,with the increasing energy consumption and environmental pollution,the call for lightweight vehicles is also Increasingly high,the bumper is an important part of the body structure,and its lightweight design is imperative.How to balance the collision safety performance and lightweight effect of the bumper is a difficult point in the design of the bumper.By studying the crash performance analysis method and structural parameter optimization method of bumper,it has important engineering significance for the safety performance improvement and lightweight design of the impact beam.This paper takes a passenger car front bumper as the research object,analyzes the research status of bumper collision safety performance and lightweight design at home and abroad,and compares and analyzes the regulations of automobile low-speed collision test formulated by various countries.Based on the enterprise's bumper design process and the automobile lowspeed collision regulations,the bumper collision safety performance evaluation method is proposed,which lays a foundation for the subsequent research.In this paper,the three-point static pressure finite element model of bumper is established and tested.The bending strength of the bumper is analyzed and verified.The bending strength of the bumper meets the design requirements.The low-speed collision finite element model of the bumper is established.The accuracy of the model were verified by the drop hammer impact test.The finite element analysis of the bumper was carried out based on the ECE-R42 regulations and the CFVSS215 regulations.The low-speed crash performance of the bumper was verified to meet the design requirements.Optimize the collision safety performance of the bumper,the axial crushing finite element model of the energy absorbing box is established and tested.The energy absorbing performance of the energy absorbing box is analyzed.By comparing the energy absorption characteristics of the energy absorbing boxes with different cross sections,the energy absorbing box section with the best energy absorption characteristics was selected,and the structural parameters of the optimal sectional energy absorbing box were analyzed by the response surface model combined with the multi-objective particle swarm optimization algorithm.optimization,the impact safety performance of the bumper is significantly improved.The lightweight design of the bumper is optimized with the beam,which with the largest mass ratio in the bumper.The thickNess of the four positions of the beam is taken as the design variable,and the low-speed collision performance,bending strength and light weight requirements of the bumper are comprehensively considered.The beam surface structure is optimized by the response surface model combined with the multi-objective optimization algorithm,so that the quality of the impact beam is reduced under the premise of meeting the collision safety performance,and the lightweight of the impact beam is realized.