Simulation of wear particle creation in asperity contacts using the finite element method

In this paper, the finite element method (FEM) is applied to simulate the sliding interaction between a hard rigid asperity and an asperity having elastoplastic material behavior and to determine the stress and deformation status in the contact region of the elastoplastic asperity. The contacting asperities on surfaces having different roughness are approximated by two-dimensional wedges of different tip angles. The stress and displacement fields induced by the sliding contact can be computed at any desired instant. Based on the FEM calculation and a mechanics analysis, it is found that the stress and deformation behavior of an elastoplastic asperity depends upon the profile geometry of both asperities in contact. Three typical contact cases distinguished by K, the relative slope between two contacting wedges, are analyzed, The results show that a wear particle may be created in one of the three wedge failure modes: Shear failure, fracture failure, and slip tongue failure. The correlation between the wedge failure modes and the wedge angles or the relative slope K is discussed, and the size of a potential wear particle in a given asperity contact case is estimated.