The influence of surface deformation on mechanical wear

The evidence for the plastic strain of wearing surfaces and its influence upon them is briefly described. Two distinct analytical approximations are available for calculating these effects: an elasto-plastic approximation, and a rigid-plastic approximation. These lead to two different damage rules and two different methods of idealizing asperity shape. Experiments and finite element analysis help to delineate the range of application of each of these models, and their associated damage rules, but it is clear that further theoretical developments are needed if wear is to be reliably predicted for most engineering contacts.