汽车低速碰撞吸能盒的耐撞性研究及优化

Research and Optimization of Crashworthiness of Energy Absorbing Box during Automotive Low Speed Collision

汽车发生低速碰撞时,动能主要由车身前部吸能盒屈曲塑性变形来吸收,从而保护与之相连的前纵梁等比较重要的汽车零部件,以减少汽车的维修成本。本文以六边形截面吸能盒为研究对象,利用非线性显示有限元分析软件Workbench LS-DYNA,研究了截面参数及壁厚对吸能盒耐撞性的影响,并在Isight软件中建立二阶响应面模型,采用多目标粒子群(MOPSO)算法,以初始峰值力和比吸能为目标函数进行多目标优化设计。优化结果表明:初始峰值力降低7.47%,比吸能增加11.14%,平均压溃力降低8.16%。

When a car is involved in a low-speed collision,the kinetic energy is mainly absorbed by the buckling plastic deformation of the energy-absorbing box at the front of the car body,so as to protect the more important auto parts such as the front longitudinal beam connected to it and thus reduce the maintenance cost of the car.In this paper,a hexagonal cross-section energy-absorbing box is used as the research object,and the nonlinear display finite element analysis software Workbench LS-DYNA is used to study the influence of cross-section parameters and wall thickness on the crashworthiness of the energy-absorbing box,and the second-order response surface model is establish it in the Isight software.The multi-objective particle swarm optimization(MOPSO)algorithm is adopted for the multi-objective optimization design with the initial peak force and specific energy absorption as the objective function.The optimization results show that the initial peak force is reduced by 7.47%,the specific energy absorption is increased by 11.14%,and the average crushing force is reduced by 8.16%.