Modeling Crack Initiation in Low Cycle Fatigue: A Review

Abstract

The typical fatigue life of a component is mainly divided into two phases: crack initiation, and crack propagation. This study is concerned with the crack initiation life as some designers regard the crack initiation as the end of the design life of the component. Crack initiation is caused by the formation of persistent slip bands that interact with the matrix leading to embryonic crack formation. There are several studies defining the point of crack initiation, and this article addresses some of these definitions. The main aim of this study is to review the different modelling methodologies for crack initiation under low cycle fatigue. These models are divided into three main types: microscopic models, damage parameters, and probabilistic models. There is no preferred methodology among the ones discussed. The choice of which model to use depends on the type of loading, the material in use, and the required level of detail. This study is intended as a reference for using one of these models or introducing modifications to enhance them.