Contact of Rough Surfaces: An Incremental Model Accounting for Strain Gradient Plasticity

Abstract

In the contact of rough surfaces, most contact patches are at the scale of micrometers, and thus, their contact deformation can be dominated by the size-dependent plasticity. In this paper, we propose a new strategy to analyze the role of strain gradient plasticity in the contact response between a realistic rough surface and a rigid plane, which modifies the incremental contact model based on the mechanism-based gradient plasticity (MSGP) theory. For several different rough surfaces with their topography measured experimentally, the relations between applied load and real contact area are derived in a simple but effective way. It is found that strain gradient plasticity significantly increases the level of mean contact pressure. The hardening effect caused by strain gradient plasticity weakens somewhat as the contact area increases. Compared with previous methods, the present model might be more efficient and of wider application.

Experimental Investigation of an Incremental Contact Model for Hyperelastic Solids Using an In Situ Optical Interferometric Technique

“…In many studies, FEM simulations offer an alternative and convenient method to investigate rough surface contact considering complex influencing factors [21], for example the nonlinearity of materials. Song [22], Zhang [23], and Jiang [24] studied the contact behaviors of rough surfaces by taking size dependence into account. Zhang and Yang [25] noted that the indentation behaviors of hyperelastic spheres primarily depend on the combined influences of substantial deformation and material nonlinearity.…”