摘要：At a fatigue crack tip, the occurrence of opening-closure behavior is already known. The opening-closure behavior of a fatigue crack tip is caused by cyclic elasto-plastic deformation of the crack tip. Fatigue strength ( S - N curve ) and fatigue crack propagation rate ( da/dN- K ) have been evaluated only in mechanical environment, and they have not been evaluated by comparison with mechanical environment and the limits of material characteristic as other fracture phenomenon.The present paper proposes a numerical simulation method using comparison with mechanical environment of crack tip and the limits of material characteristic for consideration with delayed propagation of fatigue crack. In the proposed simulation method, tensile fracture elongation after compressive plastic deformation of a mild steel have been used. In this paper, the results of the case of constant amplitude loading, block loading, and constant amplitude loading with spike load are shown.
