关键词: 白车身, 有限元, 模态分析, 振动, 频率

Abstract: 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.