A COMPONENT MODE SYNTHESIS METHOD USING THE RETRANSFORMED PHYSICAL COORDINATES

摘要

A new method is proposed for analyzing complex structures by a component mode synthesis method. In this method, mass and stiffness matrices of components are expressed by using unconstrained modes, and can be applied for both theoretical and experimental modal analysis. Several numbers of the modal coordinates of each component are retransformed to the physical coordinates of the coupling regions by using normal mode shapes. Therefore, each component can be treated as one of the finite elements in FEM analysis making it possible to connect them to each other or to connect them with nonlinear elements obtained by FEM. The dummy-mass-adding method proposed by Baker for test-based modal analysis is also applied for correcting the truncation error of higher order modes by using dummy masses at the connecting points. The technique improves the dynamic characteristics of the total system without using the residual compliance matrix. The effectiveness of the procedures is demonstrated by numerical examples.