电动汽车电池箱体结构分析与轻量化设计

Structural analysis and lightweight design of electric vehicle battery box

某动力电池箱体在随机振动试验中提示了结构强度存在风险,并期望箱体减重,为改善其性能及其轻量化需求,开展了动力电池箱体结构的有限元仿真分析与多目标优化设计。建立了动力电池箱体动静态特性模型,通过三种典型工况分析和模态分析原有结构的不足,并通过布置膨胀胶的方式弥补了该缺陷。以动力电池箱体4个关键部件的厚度为设计变量,以箱体结构的总质量、一阶模态、最大应力和最大变形量为设计响应,建立了动力电池箱体多目标优化设计模型。并利用最优拉丁超立方试验设计、径向基(radial basis function,RBF)神经网络近似模型拟合及NSGA-II优化算法进行了轻量化分析。分析结果表明:在满足动力电池箱体动静态特性性能指标的前提下,箱体质量减轻了10.2%,实现了箱体结构的轻量化。

The random vibration test results of a power battery box indicated the risk,and the weight of the box was expected to be reduced.In order to improve the performance and lightweight requirements,the finite element simulation analysis and multi-objective optimization design of the power battery box structure were carried out.Firstly,the dynamic and static characteristic model of the power battery box was established,and the deficiencies of the original structure were analyzed based on three typical working conditions and modes,and the deficiencies were made up by means of expanding glue.Then,with the thickness of the four key components of the power battery box as the design variables,and the total mass,first-order modal,maximum stress and maximum deformation of the box structure as the design responses,a multi-objective optimal design of the power battery box was established.The lightweight analysis was carried out by using the optimal Latin hypercube experimental design,RBF(radial basis function)approximate model fitting,and NSGA-II optimization algorithm.The analysis results show that:under the premise of satisfying the dynamic and static characteristics of the power battery box,the box mass is reduced by 10.2%,and the box structure is lightened.