Abstract
Keywords: Modal damping, Locally damped systems, Perturbation technique
This work deals with the complex modal analysis of locally damped linear systems. A second order perturbation technique is modified to approximate the complex eigenvalues incorporating the eigenmodes of the undamped system. The application of local damping factors successfully displaces previously estimated modal damping values and improves the system behaviour (Fischer, Engelbrechtsmüller, Keber & Nefischer, 1999). In addition to other works dealing with perturbation techniques we split the damping-matrix into a proportional part and a non-proportional part. Therefore the perturbation acts on the non-proportional part of the damping matrix only. This leads to better approximations and to exact results in case of proportional damping.