Nonlinear Structural Analysis of Complex Electronic and Electromechanical Assemblies

Abstract

The finite-element technique, which is particularly well suited to problems with complex geometries, has been extensively used in structural mechanics. For the highly nonlinear problem, however, the technique has been limited to problems with a modest number of elements for want of a solution scheme that efficiently uses computer resources. We have found that the conjugate gradient method, taken from the field of optimization, provides the required solution technique. The technique has been adapted in a finite-element formulation for structural mechanics and configured to take advantage of vector processing computer hardware, resulting in the development of two computer programs, the two-dimensional JAC1 and the three-dimensional JAC3D.2 These programs provide the analyst with powerful, efficient tools to solve for the nonlinear quasi-static response of solids. In this paper, we describe the development and capabilities of JAC and JAC3D. Following this, we present a selected group of applications relating to the structural analysis of electronic and electromechanical subsystems.