抄録
Stress intensity factor have been used as a parameter of crack growth evaluation such as fatigue or stress-corrosion cracking. Especially, welds and heat affected zones have two distributions: residual stress and yield strength. Those distributions might affect the crack growth evaluation. In other words, the potential exists to deviate from the applicable range of the stress intensity factor in those regions. In this study, the applicability of stress intensity factor was analytically investigated by comparing an elasticity solution with an elastoplastic solution of the stress state in front of a crack when the stress distribution and yield strength distribution were simultaneously present along the crack propagation path. As a result, the stress intensity factor tended to be inapplicable when the steep distributions were present in front of the crack. Additionally, the modified method of stress intensity factor for incorporating the influence of those distributions was proposed and the applicability of that was investigated.
