On the local description of wear-induced volume loss and shape changes for engineering surfaces

Abstract

The paper examines the possibility to obtain a device-independent representation of the effects induced by wear, compatible with the expectable, future development of a similitude approach to the analysis and comparison of tribological performances. Geometrical coefficients presented in former studies are redefined according to a generalised, local formulation, referred to nominal conditions and not constrained within a particular theoretical model, scale level or measurement technique. Their knowledge (from computation or experiment) allows in principle to evaluate the instantaneous distribution of wear (assessment and prediction of shape changes) and the actual kinematics (deviations from the nominal set-up relating to sliding displacement and clearance increase). First results are presented, from numerical simulations. They are consistent with the available literature; moreover, they suggest that, mainly due to compatibility restrictions, some basic geometrical features of the worn surfaces are fairly invariant with test configuration and wear law, making possible their approximated modelling from a relatively reduced set of data.