复杂结构试验模态振型高效识别方法研究

Research on effective identification method of complex structure experimental modal shape

结构模态振型的精确识别是复杂结构动力修改的基础。文中以发动机缸体作为研究对象,通过结构模态仿真识别与试验识别结果的相关性研究,验证了结构模态参数识别结果的有效性。在此基础上提出了以试验模态振型矢量为虚拟位移激励,基于结构有限元分析模型进行静力分析计算,将其静力学变形矢量等效为结构模态振型矢量的一种模态扩展分析方法,与传统试验模态振型识别方法相比,识别效率有较大改善。

The precision identification of modal shape was the fundamental work of complex structure dynamical modification. The engine block was set as the research object. The vitality of structure modal parameters dentification results was verified through the relative study of structural modal simulation identification and experiment identification results. The experimental modal shape was set as virtual displacement excitation based on this. The static deformation vector was equivalent to structural modal shape vector based on the structural static analysis calculation. This modal extended analysis was with better recognition efficiency of modal shape when compared with conventional experimental modal shape identification method.