接合界面に垂直にぶつかるき裂の塑性特異応力場

抄録

In this paper, the plastic singular stress field for a crack normal to and meeting a bimaterial interface is studied by using FEM. In the analysis, it is assumed that both materials obey Ramberg-Osgood stress-strain formulation, and have different strain hardening exponent n. Detailed results for MODE I under plane strain are investigated. When n₁ for the material with a crack is larger than n₂ for the other material without the crack, the plastic singular stress field obtained by FEM is almost the same field obtained by asymptotic analysis. However, from the FEM result, it is found that a term which is independent of the distance r from the crack tip is included in the displacement field so as to satisfy the continuity of displacement along the interface. When n₁ < n₂, the plastic stress singularity exists near the crack tip, but the stress singularity cannot be described as a power-type singularity form.