Cracking under fretting fatigue: Damage prediction under multiaxial fatigue

Fretting is one of the plagues of modern industry. It occurs whenever a junction between components is subjected to cyclic sliding, with small relative displacements at the interface of the contacting surfaces. Further cyclic bulk stresses may be superimposed on to one or both components. The investigation of fretting wear and fretting fatigue started in the early 1970s. It is responsible for premature fatigue failures and often limits the life of a component.

Crack initiation and growth under fretting contact conditions have been investigated. The fretting map concepts allow the first degradation responses of the material—no degradation, cracking and wear—to be related to a fretting regime with its corresponding local contact conditions during fretting tests.

The fretting fatigue prediction models have been developed and compared to experiments conducted either on metallic or photoelastic materials. A special emphasis has been directed towards crack nucleation and early growth during stage I, the stage I-stage II transition and stage II crack growth (crack initiation sites, orientation, growth path, formation of a branch, growth mechanism). The analysis of the different stages that comprise the crack lifetime has been carried out in order to understand the effects of diverse parameters that are thought to influence the fretting damage.