T. Yafuso et al., EVALUATION OF THE J-INTEGRAL RANGE OF FATIGUE-CRACK EMANATING FROM NOTCHES BY SIMPLE ESTIMATION FORMULAS, JSME international journal. Series A, mechanics and material engineering, 38(1), 1995, pp. 97-103
In a previous paper, the present authors discussed the path-integral e
xpression of the J-integral range, DELTAJ, for short fatigue cracks em
anating from notches, and showed that DELTAJ evaluated based on the cr
ack-opening level was an appropriate parameter for characterizing the
near-tip stress and strain fields. In this study, finite-element simul
ations of fatigue crack growth from notches were conducted. The values
of DELTAJ evaluated by the path-integral were compared with those est
imated by El Haddad's simple estimation formula proposed for short fat
igue 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
DELTAJ values evaluated by El Haddad's formula did not agree well with
the values of DELTAJ evaluated by the path-integral. In contrast, the
DELTAJ values evaluated by Dowling's formula based on the crack openi
ng level agreed well with the DELTAJ values evaluated by the path-inte
gral.