WEAR OF SURFACES: FROM MODELING OF MICROFRACTURE TO THE ANALYSIS OF THE SURFACE SHAPE VARIATION

The modeling of the wear of surfaces is considered on the micro- and macroscale from the standpoint of the contact and fracture mechanics. The specific features of wear as a particular form of fracture are indicated. Examples of the fatigue wear are analyzed by using both the one-dimensional model of damage accumulation in the surface layer (delamination model) and the thermokinetic model. The latter model permits us to simulate the multiple separation of wear particles and change in the microgeometry of surfaces, depending on the geometrical characteristics of contacting bodies, mechanical and thermophysical parameters of materials, and conditions of loading. The mathematical statement of the contact problems taking into account the irreversible change in the shape of surfaces on the macroscale is presented. This shape variation is caused by the process of the discrete separation of wear particles on the microscale. The general methods for the solution of the wear contact problems are discussed. In these methods, all contact characteristics (stress distribution, displacements due to elastic deformation and wear, approach of bodies, etc.) are functions of time. The specific features of the statement and solution of the wear contact problems for bodies the wear-resistance coefficient of which varies over the surface, and for inhomogeneous bodies are indicated. Example problems of the kinetics of the shape variation and distribution of the contact stresses are analyzed for some junctions and for the case of the polishing of homogeneous and inhomogeneous surfaces.