Fatigue crack propagation behavior under the mixed-mode condition which combined modes I, II and III was investigated in a push-pull fatigue test of the notched specimen. The notch inclined in the thickness direction was cut at the center of the plate specimen. Some fatigue cracks were initiated from the notch root, and the interaction of these cracks was observed in the crack propagation stage. However, in the present study, the crack length including notch length was treated as a single-center crack. The fatigue crack propagation rate da/dN was evaluated with effective stress intensity factor range ΔKp, eff calculated using projected crack length and normal stress in the axial direction. The crack propagation law for the present notched specimen evaluated with ΔKp, eff coincides with that of the center cracked plate.
