\documentclass[12pt]{article} \textwidth 6in \textheight 9in \topmargin 0in \headsep 0in \oddsidemargin 0in \evensidemargin 0in \date{} \pagestyle{empty} \title{Parallel domain decomposition approach to 3D boundary value problems and implementations on parallel computers} \author{Krassimir Georgiev \thanks {The author was supported in part by NATO Scientific Affairs Division and the Bulgarian Ministry of Education and Science under Grant I-505/95}} \begin{document} \maketitle \thispagestyle{empty} \centerline{A B S T R A C T} \bigskip In recent years there has been a considerable development in Domain Decomposition (DD) methods for nume\-rical approximation of partial differential equations in the framework of finite differences and finite elements methods. Among the reasons underly the interest in these techniques we mention the possibilities of determining effective pa\-rallel algorithms and implementation on modern high-speed computers mainly parallel computers with shared and distributed memory including here clusters of workstations. In this paper we are mainly concerned with the additive overlapping domain decomposition algorithms for the numerical solution of 3D elasticity systems and their implementation on parallel computers with shared and distributed memory including here clusters of workstations. Nevertheless, all the ideas into the algorithms and their implementation are valid for many others three dimensional elliptic boundary value problems with strongly varying coefficients. The system of linear equations has to be solved after a finite element method discretization is symmetric and positive definite and the Preconditioned Conjugate Gradient method with a preconditioner constructed via Domain Decomposition is used. The algorithm is highly parallelizable. The Message Passing Interface (MPI) standard both for shared and distributed memory parallel computers is used. The numerical experiments reported in this paper are obtained using two symmetric multiprocessor systems: SUN Enterprise 3000 and SUN SPARCstation 20 as well as the parallel computer with distributed memory IBM SP Power 2. A set of tables and figures illustrate the performed parallel numerical tests. They well demonstrate the parallel properties of the proposed algorithm as well as the robustness of the developed codes. \end{document}