Simulation And Optimization Research On Body Structure Of Electric Vehicle With 25% Bias Impact

In the past 30 years,with the rapid growth of car ownership and the frequent occurrence of car accidents,the number of people who lost their lives due to car collision accidents is increasing year by year.To improve the passive safety of the vehicle,to maximize the protection of the occupants from injury in the collision,has become an important issue facing the automotive industry.With the help of Hyper Works and LS-DYNA software,this paper simulates the frontal 25% bias collision process of a SUV,and analyzes the safety performance of the vehicle from the perspective of member protection.The key parts that affect the vehicle passive safety are optimized and improved.The finite element model of the whole vehicle is rebuilt,and the frontal 25% bias crash simulation test is carried out to verify the effectiveness of the optimization scheme.Specific research contents include:Obtain 25% frontal bias crash simulation results and conduct safety assessment: the energy jump ratio and mass increase rate are in the allowable range,and the simulation results are reliable.The acceleration change of the whole vehicle is reasonable,the maximum peak value is 30.7G,which is equal to the industry average value.The deformation of the door frame on the collision side and the invasion of A-pillar are large,the maximum invasion of the cowl panel and the instrument coil column is higher than the target value.The unqualified area is concentrated in the left part of the driver's body,the middle area of the left front longitudinal beam is bent during the collision,which affects the overall energy absorption effect of the longitudinal beam.The maximum energy absorption is 25.8KJ,accounting for 21.86% of the total energy of the vehicle,with general energy absorption performance.The optimization scheme for simulation results mainly includes: By using the method of orthogonal test design,the support plate and reinforcement plate are added to the easily bended area of the front longitudinal beam,and the depth and width of the second guide groove are increased.Increase the thickness of the front fender,improve the bending resistance of A-pillar,and increase the contact area of the front longitudinal beam and the rear longitudinal beam.The response surface analysis method is used to design the energy absorption box structure for the automobile.From the optimization results of 25% frontal bias collision: After optimization,the peak acceleration of collision side is reduced by 5.86%,the area of the disqualified area of the cowl panel is reduced,and the maximum intrusion amount is reduced by 46.1mm,the maximum invasion of A-pillar is reduced by 52.9mm.The front longitudinal beam absorbs more energy of 5.04 KJ,and the energy proportion is increased by 4.24%.Finally,full width frontal crash simulation tests are carried out on the vehicle models before and after optimization.According to the simulation results of the optimized vehicle model: The deformation of the front longitudinal beam is good,and the proportion of energy absorption to total energy is increased by 6%.The peak acceleration of the whole vehicle is reduced by 9.8%,and the maximum intrusion of the cowl panel is reduced by 30.1mm.In a word,the research of this subject improves the crash worthiness of the target vehicle.The research method and optimization scheme have reference significance for improving the crash safety of electric vehicles and fuel vehicles.