基于刚度和模态灵敏度分析的轿车车身轻量化研究

Study on Weight-Reduction of Car-Body Based on Stiffness and Modal Sensitivity Analysis

以某轿车白车身为例,建立有限元模型,以车身结构的刚度和模态有限元计算为基础,经灵敏度分析方法确定优化设计变量,以车身结构质量的最小化为目标,在保证车身刚度和模态性能的前提下,优化车身零件的厚度,从而实现车身结构的轻量化,车身减轻的重量为原来的3.6%,车身结构的刚度和主要模态频率也都获得不同程度的提高。

A FE model for a car-body is built.On the basis of finite element analysis of the stiffness and modal of the car-body,the optimization design variables are determined through the sensitivity analysis of the stiffness and modal.Then,an optimization of the thickness of body panels is conducted with an objective of minimizing the mass of the body structure and meeting the requirements of stiffness and modal properties.So the weight reduction of car body is realized.Result of the optimization shows that the total mass of the car body is reduced by 3.6%,while the modal frequency and stiffness are somewhat raised.