Author(s)

Y. Ochiai

Abstract

In general, internal cells are required to solve elastoplastic problems using a conventional boundary element method (BEM). However, in this case, the merit of BEM, which is ease of data preparation, is lost. Triple-reciprocity BEM can be used to solve two-dimensional elastoplasticity problems with a small plastic deformation. It has been shown that three-dimensional elastoplastic problems can be solved, without the use of internal cells, by the triple-reciprocity BEM and initial strain method. In this study, an initial stress formulation is adopted and the initial stress distribution is interpolated using boundary integral equations. A new computer program was developed and applied to solving several problems. Keywords: elastoplastic problem, initial stress method, BEM. 1 Introduction Elastoplastic problems can be solved by a conventional boundary element method (BEM) using internal cells for domain integrals [1, 2]. In this case, however, the merit of BEM, which is ease of data preparation, is lost. On the other hand, several countermeasures have been considered. Ochiai and Kobayashi proposed the triple-reciprocity BEM (improved multiple-reciprocity BEM) without the use of internal cells for two-dimensional elastoplastic problems using an initial stress and strain formulations [3]. By this method, a highly accurate solution can be obtained using only fundamental solutions of a low order. It has been shown by Ochiai that three-dimensional elastoplastic problems can be solved, without the use of internal cells, by the triple-reciprocity BEM and initial strain method.

Keywords

elastoplastic problem, initial stress method, BEM.