Algorithm for Simultaneous Determination of Modal Frequencies and Modal Vectors of a Dynamic Impedance Matrix

摘要

An iteration routine was installed in a distributed element package for dynamic analysis of spacecraft structures. The iteration routine determines simultaneously the eigenvalues and related eigenvectors of a dynamic stiffness matrix given in implicit form, i.e., containing poles. Unlike other routines with the same objective, the routine does not need an a priori knowledge of the poles of the matrix and it works also for gyroscopic and/or nonconservative systems. The installed version, however, is specialized to conservative and nongyroscopic systems. The main intention of this installation is to test the routine in a real world environment in order to decide on its use for nonconservative systems. Test runs are satisfactory, except if poles and zeros of the system are very close, when the scaling of the eigenvectors is poor.