Abstract: We proposed an adaptive method for calculating the sensitivity of the system eigenvector. Firstly, the mid-modes to be calculated were determined adaptively. Secondly, an iterative algorithm was constructed to adaptively approximate the unknown low-order modal and high-order modal contributions. Finally, the effectiveness of this proposed method was verified by numerical example. The results show that this method only needs to decompose the shifted stiffness matrix once, and does not need to decompose other matrices.

Key words: frequency band, mid-eigenvector, sensitivity, spectral radius, adaptive algorithm