Abstract: The finite element analysis of the simplified body in white of a certain vehicle and its lightweight based on HyperMesh, in order to reduce the body mass without affecting the body stiffness. After the computer aided engineering (CAE) model is built, the static stiffness and modal cloud image are calculated by setting the boundary conditions, and the dimensional optimization is carried out by the sensitivity screening plate, and the mass and stiffness changes before and after are compared. The results show that the mass is reduced by 17.35 kg, the weight reduction ratio is about 4.3%, and the change of body stiffness is within the range, and the purpose of lightweight is achieved.

Key words: Body; Lightweight design; Static stiffness; Free mode; Sensitivity analysis

摘要： 基于 HyperMesh 的某款车型简化后的白车身有限元分析及其轻量化，以减少车身质量 且不影响车身刚度。建完计算机辅助工程（CAE）模型后，设定边界条件计算得出静态刚度 和模态云图，通过灵敏度筛选板件进行尺寸优化，对比前后质量以及刚度变化情况。研究结 果得出质量减少 17.35 kg，减重比例约为 4.3%，且车身刚度变化在符合范围之内，达到轻量 化目的。

关键词: 车身；轻量化设计；静态刚度；自由模态；灵敏度分析