抄録
In previous paper, it was shown that J_<IC> fracture criterion was able to estimate the fracture in both linear and non linear regions. And it was comfirmed that J-value was calculated by the finite element method. In this paper, we apply J_<IC> fracture criterion to the fracture of Tee Connection modeled Steel Structure Beamto-Column Connection. When we apply non linear fracture mechanics, we confuse that a crack is very short. A crack of the steel structure is generaly very short, but J-integral is defined with the deep notch. So we investigate that the crack length have an effect on J-integral, and apply J_<IC> fracture criterion to Tee welded joints. The results are shown as follows.(1) A condition of a crack initiation changes with stress conditions. And tbe condition of a crack initiation by J_<IC> fracture criterion is equal to the condition of it by a strain. (2) J-values of crack initiation becomes small in proportion to a multi-strees-condition, and approach a critical J_<IC>-value. This J_<IC> fracture criterion can be applyed to the steel frame constructions.
