频率集聚时模态分析的移位摄动法

PERTURBATION ANALYSIS OF VIBRATION MODES WITH CLOSE EIGENVALUES BY EIGENVALUE SHIFT

模态分析的矩阵摄动法在灵敏度分析和重分析中有广泛的应用。然而,已有的孤立特征值摄动法和重特征值摄动法都难于用来解决密集模态的摄动问题。本文提出了特征值的移位措施,将密集特征值组移位为重特征值,从而可用重特征值的摄动法来解决密集模态的摄动问题。文中分析了频率集聚时特征向量的性质,讨论了本文方法的合理性。

Matrix Perturbation methods are widely used in sensitivity analysis and reanaly-sis of Vibration modes. However, the perturbation methods for distinct or repeated eigenvalues can not be directly used to deal with the vibration modes with close eigenvalues. This paper presents a new approach to perturbation analysis of vibration modes with close eigenvalues using eigenvalue shift technique . In this new method, the perturbation problem of vibration modes with close eigenvalues is transformed into the problem associated with repeated eigenvalues through eigenvalue Shift. This paper discusses the properties of vibration modes with close eigenvalues and rationality of this new method.