ABSTRACT
The vast majority of contact problems in engineering practice are non-Hertzian that require numerical solutions. In-depth understanding of material interaction at a contact interface has been a great challenge, mainly due to the following complexities:
Irregular geometry of contact interfaces related to the topographic nature of contacting rough surfaces that may be multi-scale and random to a certain degree;
Complicated interfacial conditions, such as fluid–solid interaction, the influences of boundary physics and tribochemistry, and phenomena related to various types of relative motion, as well as dynamic loading in different modes;
Inelastic material behaviors, such as elastic-plasticity, thermally induced variations, and material work hardening, thus, stresses and strains do not follow the simple linear relationship;
Inhomogeneous and anisotropic material systems, such as surface layers, coatings, impurities, composite matrix fillers, imbedded particles, fibers, inclusions, defects, voids, and cracks that are commonly seen in engineering reality;
Influences of multiple fields, such as the thermal, electrical, chemical, magnetic fields and their possible combinations, in addition to mechanical interactions.
