A 2-D model for friction of complex anisotropic surfaces

The friction force observed at macroscale is the result of interactions at various lower length scales, which are difficult to model in a combined manner. For this reason, simplified approaches are required, depending on the specific aspect to be investigated. In particular, the dimensionality of the system is often reduced, especially in models designed to provide a qualitative description of friction properties of elastic materials, e.g. the spring-block model. In this paper, we implement for the first time a two dimensional extension of the spring-block model applied to structured surfaces, aiming to investigate by means of numerical simulations the frictional behaviour of a surface in the presence of features like cavities, pillars or complex anisotropic structures. We show how friction can be effectively reduced or controlled by appropriate design of surface features