Experimental and numerical study on the multi‐site fretting fatigue crack initiation of press‐fitted axles

Abstract

AbstractIn this study, fretting fatigue tests were conducted to gather information on both fretting fatigue and fretting wear. Subsequently, an evaluation methodology that combined the Modified Wöhler Curve Method (MWCM) with the theory of critical distance (TCD) was established to investigate multi‐site fretting crack initiation. The results showed that the fretting fatigue damage could be reasonably evaluated using the MWCM equivalent stress σMWCM. σMWCM is greatly influenced by both bulk stress and fretting wear‐induced stress concentration. The stress field close to the wear boundary increased due to the continuous fretting wear, leading to an increase in σMWCM; meanwhile, the bulk stress near the wear boundary decreased as the crack propagated, resulting in a decrease in σMWCM. The combined effect of the fretting crack propagation and wear caused σMWCM, which was located within an annular strip of the axle, to exceed the critical value, causing the multi‐site fretting crack initiation.