Matrix perturbation for structural modification in non-self-adjoint systems

This paper presents an improved matrix perturbation technique for structural modification in non-self-adjoint systems. The main objectives are two-fold: one is to study the influence of the omitted coefficients in modal expansion in the existing methods, and then to modify the perturbed eigensolutions by introducing two simple but reasonable normalization conditions; the other is to investigate the perturbation technique for the dynamic reanalysis of non-self-adjoint systems with distinct and repeated eigenvalues. Illustrative examples are given to verify the proposed method. The errors induced by the present method and other methods are analyzed. It is shown that the present method gives the highest accuracy.