Abstract
From practical standpoints, it is very important to set up the evaluation procedures of fracture toughness of heterogeneous materials such as welded joints. In this paper, the finite element analyses of the J-integral extended to the problem of a crack in heterogeneous materials were carried out on the compact tension type welded joints in order to examine and clarify the unsymmetric deformation characteristics of welded joints, the fracture path of them in mixed mode conditions and the relation between J-integral and total/local crack tip opening displacement. Through calculation results, the validity of crack tip characterising role of J-integral was proved. Moreover, it was confirmed that the J-integral correlated to the total crack tip opening displacement.
