Propagation behavior of long crack in low cycle fatigue regime
Makabe Chobin; Hiyane Masumi; Kaneshiro Hideo
Abstract:Fatigue crack propagation behavior of a center cracked plate was observed by an optical microscope in the low cycle fatigue regime. The fatigue tests were carried out under a stroke-controlled condition. The crack propagation rate da/dN was proportional to the crack length a and the crack propagation law could be expressed by da/dN = C etaa, where C and a are constants and Det is the reversed nominal strain range. Also, the nominal stress at maximum load was inversely proportional to the crack length normalized by specimen width a/W. Furthermore, the crack growth behavior in the case of low cycle fatigue of the present experiment was compared to that in the case of ductile fracture of a center cracked plate. In both cases, the crack growth behavior could be correlated with the crack length and the crack opening geometry. Key Words:low cycle fatigue, stroke control, crack propagation, center cracked plate, crack length, nominal stress