Cracking under fretting fatigue: damage prediction under multiaxial fatigue
Résumé
Fretting is one of the plagues of modern industry. It occurs whenever a junction betweencomponents is subjected to cyclic sliding, with small relative displacements at the interface of thecontacting surfaces. Further cyclic bulk stresses may be superimposed on to one or both components. Theinvestigation of fretting wear and fretting fatigue started in the early 1970s. It is responsible for prematurefatigue failures and often limits the life of a component.Crack initiation and growth under fretting contact conditions have been investigated. The fretting mapconcepts allow the first degradation responses of the material—no degradation, cracking and wear—to berelated 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 conductedeither on metallic or photoelastic materials. A special emphasis has been directed towards crack nucleationand early growth during stage I, the stage I – stage II transition and stage II crack growth (crack initiationsites, orientation, growth path, formation of a branch, growth mechanism). The analysis of the differentstages that comprise the crack lifetime has been carried out in order to understand the effects of diverseparameters that are thought to influence the fretting damage.