Abstract
In a previous paper, the present authors discussed the path-integral expression of the J-integral range, for short fatigue cracks emanating from notches, and showed thatΔJ evaluated based on the crack-opening level was an appropriate parameter for characterizing the near-tip stress and strain fields. In this study, finite-element simulations of fatigue crack growth from notches were conducted. The values ofΔJ evaluated by the path-integral were compared with those estimated by E1 Haddad's simple estimation formula proposed for short fatigue cracks at notches, and with those estimated by Dowling's formula for deep cracks and by Cho's formula for short cracks at notches. The ΔJ values evaluated by E1 Haddad's formula did not agree well with the values of ΔJ evaluated by the path-integral. In contrast, the ΔJ values evaluated by Dowling's formula based on the crack opening level agreed well with the ΔJ values evaluated by the path-integral.
