Improved Dynamic Substructuring on

For solving the eigenvalue problem of a structural system having a large number of degrees of freedom the authors introduced in 6] the improved condensation method using the Rayleigh functional of the exactly condensed nonlinear eigenvalue problem. In this paper we discuss the implementation of the method for substructured problems on a distributed memory MIMD Computer. Examples are presented which demonstrate the eeciency of the method at least if the number of substructures is not too large. INTRODUCTION In the dynamic analysis of structures using the nite element method very large eigenvalue problems arise, and condensation is often employed to reduce the number of degrees of freedom to manageable size. To this end Guyan 2] and Irons 3] introduced a method which is called static condensation nowadays and which is based upon eliminating a large number of coordinates (called slaves) and retaining a small portion of the unknown coordinates (called masters). However, it is well known that often only very few eigenvalues at the lower end of the spectrum are achieved with reasonable accuracy. Several attempts have been made to increase the accuracy of the eigen-values of the condensed problem. In 6] we took advantage of the structure