Influence of compressive cyclic loading on crack propagation in AM60B magnesium alloy under random and constant amplitude cyclic loadings

An experimental investigation is carried out to study the influence of compressive loading cycles on the crack propagation response of AM60B magnesium alloy. Random and constant amplitude loading scenarios with various compressive loading contributions (or stress ratios) are applied on a center-cracked plate, and their fatigue response is examined. te element analysis is also conducted to evaluate the stress distribution around the crack tip at various stages of cyclic loading for various stress ratios for the plates considered in the experimental investigation. The relation between the residual plastic zone size and crack propagation rate is critically examined. It is observed that the size of the residual plastic zone has a significant influence on the crack propagation rate. As a result, new parameter is defined, which captures the influence of the compressive loading on the crack propagation rate.