大規模降伏下におけるJ積分の適用範囲とき裂先端近傍応の応力場と応力三軸度の評価

抄録

Crack growth under the elastic-plastic fracture is an important issue of the structural integrity, because seismic wave causes low cycle fatigue in the engineering structure. We developed modeling technique for CT specimen with shear-lip surface including crack front lines. The validity of the FE model was evaluated by several fundamental analysis. The relationship between total reaction force and load point displacement and crack propagation rate and ΔJ relationship are computed for a validity of the simulation. ΔJ computed by the numerical simulation agrees with the experimental one. However, crack propagation rate and ΔJ shows linear relationship in logarithm scales like Paris’ law, however its fluctuation is very large. In order to obtain smoothed physical quantities along crack front, an application phase analysis should be conducted using approximate crack propagation rate.