鋼材の低サイクル疲労亀裂発生寿命に関する研究

抄録

Fatigue crack initiation life of notched plate under axial load for mild steel and high tensile strength steel, HT 60, was experimentally investigated to apply a formulae derived from a cumulative damage law proposed by the authors. From the test results, validity of the proposed formulae was proved. and a relation between cyclic plastic strain range Δ_<εp> at the notch root and crack initiation life N_c was expressed by a function of elastic stress concentration factor of the notch K_t. This formula showed that both unnotched and notched specimen have approximately the same life when the plastic strain rang of specimen with K_t smaller than three is equal to that of unnotchod specimen.