Investigation in improving the computational accuracy of local “uncracked stress” in pipe-shaped structure using isoparametric boundary element method

Abstract

This paper is intended for studying the computational accuracy and the fitting problem of “uncracked stress” in pipe-shaped structure details using isoparametric boundary element method. At first, the influences of different kinds of discretion plan on computational accuracy are studied by considering the simplest pipe-shaped structure—a thick wall cylinder, then the “Uncracked stress” distribution of typical pipe-shaped structures—“—shaped” and “T-shaped” junctions is calculated. In order to improve the fitting accuracy of “uncracked stress”, more internal nodes are added to the local area while more interpolation points are added to boundary element where the local stress gradient is great. The study shows that the computational accuracy is satisfactory even a few boundary elements and internal nodes are used, when the eight—node isoparametric boundary element method is adopted.