抄録
The J contour integral has been applied mainly to homogeneous cracked bodies, but not to heterogeneous cracked ones. In this paper, the FEM type analyses of J contour integral were performed on heterogeneous cracked bodies of linear elastic or elasto-plastic materials, especially those of three-phase materials, such as welded joints. From analytical and numerical standpoints, the revised J-integral formula offered in this paper was verified to be path independent. Furthermore, it was extended to the problem of heterogeneous cracked bodies. Through these results, the validity of the solutions and the effect of the strength ratio of weld metal to base metal on the J-value were revealed. Moreover, the J-integral was proved to control the normal strain ahead of the crack tip of three-phase materials.
