Crack Initiation Under Low-Cycle Multiaxial Fatigue

This study is devoted to the determination of a criterion for predicting crack initiation under low-cycle multiaxial fatigue. Here crack initiation, Ni, is defined as the number of cycles needed by the final microcrack to reach one grain size. The tests which were carried out at room temperature on Type 316L stainless steel and Inconel 718 alloy included (a) reversed tension-compression (b) reversed tension-compression with a superimposed steady torque, (c) pulsated tension-compression with a stress ratio R? such that -0.5