Stress Intensity Factor Analysis of Interface Crack Using Boundary Element Method. 1st Report. Application of Virtual Crack Extension Method.

Abstract

This paper presents a new method for the stress intensity factor analysis of two-dimensional problems including a mixed mode interface crack between dissimilar materials. The virtual crack extension method, which is usually utilized together with the finite element method, is an excellent method for evaluating the stress intensity factors. In the present paper, the virtual crack extension method is combined with the boundary element method. A stress analysis is carried out by the boundary element method, and then the virtual finite elements are assumed around the crack tip. The nodal displacements of these virtual finite elements are evaluated as internal points. At first, we applied the present method to a center-cracked plate under tension. Furthermore, we analyzed a plate with a center interface crack and a plate with a center slant interface crack between dissimilar materials subjected to tension. It is found from these analyses that the present method gives very accurate results and that the accuracy of the solution is insensitive to the size of the virtual finite elements around the crack tip.