STUDY ON ERRORS OF APPROXIMATE DECOUPLING ANALYSIS FOR NON-PROPORTIONALLY DAMPED STRUCTURAL SYSTEMS

For dynamic analysis of non-proportionally damped structural systems,one common procedure is to decouple the motion equations of the systems by using a selected diagonal matrix being equivalent to the normalized damping matrix.In this paper,the approximate errors introduced by this method are studied,not only deriving the norm of the errors but also obtaining the bounds in which the exact solutions lie. The results show that the approximate decoupling method can be applied in certain cases.