Mass and Stiffness Matrices Updating Using the First Modal Data

Abstract

This paper presents a new direct approach to simultaneously update the analytical mass and stiffness matrices in an undamped model .First, we assume that the difference between the finite element model and the real model is little. Second, only by utilizing the first order modal data orthogonal normalization conditions and eigen equations , we derive the updated matrices. Third, the method can maintain matrices symmetry and sparsity and preserve system connectivity. The merit of the proposed method is simple and accurate in a practical engineering computation. Finally,a numerical example is given to demonstrate the accuracy and effectiveness of the presented updating method.