THE STRESS CONCENTRATION AND ITS MODERATION AROUND THE APEX OF DISSIMILAR MATERIALS

Abstract In this paper, the stress distribution around the apex of dissimilar materials is calculated for both two and three dimensional bonded structures by using an improved Boundary Element Method (BEM), and the order of stress singularity is obtained from the numerical solution. It is shown that the numerical solution is very accurate even near the boundary or apex, and for the samples of ceramics (Al2O3) bonded with Cu, it is proved that the order of the stress singularity obtained in this way is in good agreement with Bogy's theory and the numerical solution can be used as an evaluating standard of nondestructive testing. For the three dimensional bonded structure, it is found that the stress singularity is very strong around the apex. This reveals that the possibility of crack generation in this area is very high. Through some detailed investigations about the stress field, a simple method to moderate the stress singularity is suggested.