The Enriched Element for Finite Element Analysis of Three-Dimensional Elastic Crack Problems

Abstract

An improved procedure for enriching three-dimensional isoparametric elements with the asymptotic crack front solution is described. Results from finite element calculations, involving these enriched elements, for the three-dimensional problems of a straight crack in plane strain and an axisymmetric penny-shaped crack which demonstrate the high degree of accuracy attainable are presented. Some finite-element solutions for through-crack and surface flaw problems are then reported showing the influence of a free surface on the variation of the stress intensity along the crack edge. Special treatments of the crack front-free surface stress intensity are implemented and the results discussed.