非比例阻尼系统动力修改的摄动分析

PERTURBATION ANALYSIS FOR STRUCTURAL DYNAMIC MODIFICATION OF NON-PROPORTIONAL DAMPED VIBRATION SYSTEMS

讨论了对非比例阻尼振动系统作小修改时，其复频率和复振型的摄动分析方法。当振动系统的质量矩阵、刚度矩阵和阻尼矩阵有较小修改时，不重复求解大型复广义特征问题，在已知初始系统复模态参数的基础上进行复模态坐标变换，用矩阵摄动法给出修改系统的频率、阻尼比和复振型。算例表明，将这种方法用于非比例阻尼振动系统的动力修改，计算简单，费用经济，精度较高，因此是一种行之有效的分析方法。

A perturbation method for analyzing the complex frequencies and modes of non-pro-portional damped vibration systems is presented.When the mass,stiffness and damping matrices of the original system vary a little,carrying out the complex modal coordinate transformation based on the original known complex modes and using the matrix perturbation method,the fre-quencies,damping ratios and complex modes of the updated system can be obtained without re-solving a new large generalized complex eigenvalue problem.The numerical example shows that the present method is simple,economic and highly accurate.