Computation of eigenvector derivatives using a shift-system dynamic flexibility
Zhang De · Jisuan lixue xuebao · 2000
HT5SS]When two dynamic flexibility formulae proposed early by author are used in the analysis of eigen derivative for free structure with rigid\|body motion, the coefficient matrix of governing equation for solving matrices A\-0, A\-1,… to be determined in the power series is singular stiffness matrix K. To solve matrices A\-0, A\-1,… one has to complement some independent equations associated with rigid\|body motion, so that the band\|state characteristic of matrix K is broken. In order to improve computational efficiency, a shift\|system dynamic flexibility expression is developed by using shifting frequency in this paper. The coefficient matrix of governing equation for solving matrices A\-0,A\-1,… in the shift\|system dynamic flexibility expression is a shifted stiffness matrix K\+* that always is non\|singular and possesses the band\|state characteristic of original matrix K. Thus the computational efficiency of the method presented in this paper is obviously better than that of early methods.