Automated Multi-Level Substructuring:Theory

Richard B. Lehoucq and Jeff Bennighof

Sandia National Laboratories

PO Box 5800, MS 1110

Albuquerque, NM 87185-1110

And

The University of Texas at Austin

Department of Aerospace Engineering

and Engineering Mechanics

W.R. Woolrich Laboratories (WRW)

Room 117D - Mail Code: C0600

Austin, TX 78712-1085

Abstract

A new method for frequency response analysis of very large finite element models of structures, known as Automated Multi-Level Substructuring (AMLS), has recently been developed. Large FEM models typically having over one million degrees of freedom are automatically subdivided into thousands of substructures. The response of the structure is represented in terms of substructures eigenvectors. These eigenvectors are much less expensive to obtain than the global eigenvectors required for conventional modal frequency response analysis. As a result, the computational cost of the analysis is substantially reduced when AMLS is used in place of traditional methods. This presentation will give an overview of an analysis of AMLS.