Material Sensitivity to Mean Stress: A Review of the Walker Fatigue Life Prediction Parameter and a Modified SWT Fatigue Life Prediction Parameter
Accurate fatigue life predictions are important when designing components subject to repeated loading cycles. The Walker model is a popular choice for predicting fatigue life during cyclic loading with non-zero mean stress effects. The Walker model suggests that sensitivity to non-zero mean stress is dependent on material. This work serves as an overview of the Walker fatigue life model, for which a life prediction parameter is derived from the Walker equivalent stress. In addition, this work analyzes an alternative fatigue life prediction model that considers material sensitivity to mean stress addition: a modified SWT parameter proposed by Lv et al. Both the Walker model and the modified SWT model were utilized for existing data and compared to the original SWT model. Both the Walker model and the modified SWT model provided equivalent or better life predictions than the SWT model for non-zero mean stress fatigue data analyzed.