Models of Anisotropic Friction Depending on a Sliding Path Curvature

Abstract

Physical properties of solids and surfaces are very often non-homogeneous, and they can form different field singularities in a contact area between two bodies (concentric circles, ellipses, spirals etc.). The phenomenon refers to complex physical properties of materials (e.g. wood, crystals) or to specific techniques of manufacture and finishing. Non-homogeneous physical properties of solids and surfaces can generate a non-homogeneous anisotropic friction in the contact. This is the case where friction depends on the position of a contact point with respect to a singular field center. Then, the frictional anisotropy follows on the one hand from the physical properties of the surface, on the other hand it can additionally depend on a sliding path in this surface. This fact should be included in the mathematical formulation of the friction law. In the contact surface with complex properties besides rectilinear particular friction directions also curved particular directions can exist.