Study on Optimization of Automobile Crash Box Considering the Influence of Strain Rate

The strain rate is one of the main factors that determines the yield strength of the material, which has a great influence on the accuracy of the numerical simulation of the automobile crash box. The numerical simulation of the crash box considering the strain rate of the material is carried out, and found that the impact force on the longitudinal beam of the car body is large and the energy absorption ability is small during the collision process. Through two sets of optimization studies, the results show that increasing the double-sided convex groove at the proper position of the front crash box can effectively reduce the impact force transmitted to the car body at the initial stage of the collision, and at the same time reduce the energy absorption ability of the crash box; Adding double-sided grooves at the front crash box can make the crash box collapse smoothly, cut down the collision force transmitted to the car body, and increase the energy-absorbing ability. At the same time, the results of the two optimization designs are verified by the methods: the sense of crushing deformation and the average square of all nodes velocity.