Stress-strain response was analyzed in the cross section of circumferentially notched components by the finite element method. Then, the cyclic J-integral range, ΔJ was estimated for the semielliptical surface crack and for the circumferential crack. The growth rate of the surface crack was successfully plotted against the estimated J-integral range under low-cycle fatigue loading.
Furthermore, the transition from the semielliptical surface crack to the circumferential crack, which occurred in the fatigue crack growth process in the acutely notched cylindrical component, was reasonably analyzed in terms of elastic-plastic fracture mechanics.
Finally, the low-cycle fatigue lives of the dully and acutely notched cylindrical components were satisfactorily evaluated through the analysis of the growth of the surface and circumferential cracks.