Three-Dimensional BEM Analyses of Dissimilar Material Joints and Interface Cracks.

Abstract

This paper represents the 3D BEM analyses of the stress distribution and the stress singularity on the interface between dissimilar materials, and also the stress intensity factors for an interface crack. The results obtained are compared with 2D results under the plane strain or plane stress state, and the validity of the plane approximation for the interface problems is discussed. The condition for the stress singularity at the edge of the interface to disappear is clarified in the 3D case. The distribution of the stress intensity factors (K1, K2, KIII) for the through interface crack along the crack front is presented for various material combinations. It is found that the plane strain state exists near the center of a dissimilar material plate if the thickness is large enough. But the plane stress state does not exist even if the plate is very thin.