A Comparison Between Critical-Plane and Stress-Invariant Approaches for the Prediction of Fretting Fatigue Crack Nucleation

Abstract

The phenomenon of fretting fatigue can cause crack nucleation at the contact interface due to multiaxial loading conditions. The nucleation phase may take a significant proportion of life under fretting fatigue, which leads to micro crack initiation. There are several approaches in vogue to estimate crack initiation life. The current study, however, aims to compare two approaches, namely, Critical Plane (CP) approach and Stress Invariant (SI) approach. Smith Watson Topper (SWT), McDiarmid (MD) parameters, which represent critical plane approach, whereas, Crossland parameter (CL), which represents SI approach, are adopted for this purpose. These parameters are applied to cylinder on a flat configuration and predicted numerical results are also compared with experimental results from literature. It is observed that, under fretting fatigue conditions, life prediction capability of critical plane approach is better than stress invariant approach especially at large number of cycles to failure.