Elastic analysis using finite elements with constraints formulated by boundary integral equations

A coupled approach linking a direct boundary integral equation to the subdomain of elastic solid discretized by means of finite elements is presented. In the proposed method, the computational domain is split into two parts by an arbitrary artificial boundary. The finite region adjacent to the actual boundary is discretized with finite elements consisting of one or two rows only in the radial direction up to the artificial boundary. Then the constraint equations specified on the artificial boundary are formulated with boundary integral equation straightforwardly, in which the source points are laid on the actual boundary discretized with boundary elements. Due to the avoidance of singularity problems inherent in the boundary element formulation, this method is very efficient and easy to implement in an isoparametric element environment. Three example problems including bounded and unbounded media are presented to demonstrate the effectiveness of the method. By the help of such exact boundary constraints, the results are very accurate even with a small number of elements. (C) 2000 Elsevier Science B.V, All rights reserved.