基于耐撞性的汽车多腔结构吸能盒轻量化设计

The Lightweight Design of Automotive Multi-Cavity Structure Energy-Absorbing Box Based on Crashworthiness

为了在保证耐撞性的前提下实现汽车吸能盒的轻量化,通过有限元碰撞仿真对比确定了符合要求的吸能盒结构,并采用基于近似模型的优化方法获得了性能最优的多腔结构吸能盒设计方案。首先建立了多种截面形状吸能盒的有限元模型,使用有限元软件进行了碰撞仿真分析。通过对单腔结构吸能盒与不同截面的多腔结构吸能盒的碰撞性能进行评价与决策,确定了符合要求的吸能盒截面形状。其次对此截面吸能盒的内外壁厚进行试验设计,拟合了碰撞性能参数的响应面模型,建立了以吸能盒内外壁厚作为设计变量,以比吸能最大作为目标函数的数学优化模型,并进行了优化设计。结果表明,采用该方法得到的最优方案能够在保证碰撞安全性的基础上实现多腔结构吸能盒的轻量化设计。

In order to achieve the lightweight of automotive energy-absorbing box on the premise of ensuring crashworthiness,the structure of energy-absorbing box is determined by finite element collision simulation comparison,and the optimal design scheme of multi-cavity structure energy-absorbing box is obtained by using the optimization method based on approximate model.At first,the finite element models of energy-absorbing box with various cross-section shapes are built,and the collision simulations are conducted based on the finite element software.By evaluating and deciding the collision performance between single-cavity energy-absorbing box and multi-cavity energy-absorbing boxes with different cross-sections,the required cross-section shape of energy-absorbing box is determined.Then the experimental design of the inner and outer wall thickness of the energy-absorbing box is carried out to fit the response surface model of the collision performance parameters.A mathematical optimization model is established,in which the inner and outer wall thickness of energy absorption box is taken as design variable and the maximum specific energy absorption is taken as objective function,and the optimal design is carried out.The results show that the optimal scheme obtained by this method can achieve the lightweight design of multi-cavity structure energy-absorbing box on the basis of ensuring collision safety performance.