Mechanical analysis of coated materials undergoing fretting fatigue in a cryogenic environment
Fretting damage, also known as small-amplitude oscillatory sliding motion, can lead to catastrophic failure in many industrial applications. An understanding of fretting fatigue and its reproduction in laboratory tests have enabled an evaluation to be made of the fretting resistance of homogeneous substrate. To reduce the damage caused by fretting fatigue, increasing use has been made of coatings or treatments that result in inhomogeneous solids. From a theoretical point of view, ascertaining the mechanical behaviour of materials so modified is quite complex due to insufficient definition of the contact parameters. This present study seeks to analyse a layered medium undergoing fretting fatigue in a cryotechnical environment and the improvement in its fretting fatigue resistance. The first step of the analysis of a layered alloy is the determination of the new contact parameters in elasticity, and the second is the characterization of the elastic-plastic coefficients of the strain-hardening law. An evaluation of the lifetime before crack initiation will close the analysis.