某轿车白车身模态分析与试验研究

以某轿车白车身为研究对象,基于有限元和静动态理论,在HyperMesh软件中,对白车身焊点进行合理描述,建立了白车身有限元模型.用MSC.Nastran软件对白车身进行了模态模拟分析,得到白车身的固有频率及对应的各阶振型之间的关系;在试验中,采用固定式激振器对白车身进行单点激振,用多点拾振方法采集响应信号,通过对响应信号的分析处理,得到白车身的固有频率及对应的振型关系.将试验结果与理论分析结果进行对比,验证了白车身有限元模型的有效性.基于有限元模型,提出利用各阶模态的应变能分布,确定车身结构弹性变形最大位置的方法,可以有针对性地加强车身的局部刚度.利用有限元模型对白车身进行模态分析,对于提高车...

Modal Analysis and Testing of a Certain White Bodywork

The modes of vibration of a certain saloon car's white bodywork was investigated. According to FEM and static/dynamic theory, a FEA model of the white bodywork was developed describing reasonably its welding points with the software HyperMesh. A modal simulation was done to analyze the white bodywork by the software MSC. Nastran, so as to get the relationship between its natural frequency and corresponding modes of vibration of different orders. In test a fixed resonator was used to conduct a single-point resonance for the white bodywork, with relevant response signals picked up at multiple points to process and analyze them, thus obtaining the relationship between the natural frequency of the white bodywork and corresponding modes of vibration. Comparing the results of the simulation with that of test, the validity of the FEA model is verified. A new method is therefore proposed to determine the position where the maximum elastic deformation takes place by the strain energy distribution of the vibration modes of different orders. It can be used to improve the local rigidity of the bodywork. The modal analysis of white bodywork by FEA model is also important to improving the dynamic properties of bodywork, optimizing its structure, shortening R and D period and saving costs.