Real contact area and friction: an overview of different approaches

The aim of this chapter is to show and analyze and discuss the results obtained by the Finite Element Model (FEM) in the calculation of the Real Contact Area (RCA) of rough contacts with the presence of friction which plays a key role in mechanical contacts, for its relationship with other variables such as adhesion, wear, etc. The results of the simulations were compared with the outcomes obtained from three consolidated statistical approaches found in scientific literature: the Kogut and Etsion; Cohen, Kligerman and Etsion; and Li, Etsion and Talke models. The investigated conformal coupling consists of rigid smooth plane against a rough deformable plane shaped by a series of hemispheres which represent the surface asperities. A total of 15 samples with different mechanical properties and arithmetical roughness values were considered. The results of the FEM model, obtained in hypothesis of absence of asperities interaction, were achieved in terms of RCA, contact pressure, asperities deformation.