The normal approach between rough flat surfaces in contact

Abstract

The relationship between the normal approach and load for a variety of rough flat surfaces has been considered experimentally and theoretically. The experimental values of normal approach measured by a capacitance technique correlate well with the theoretical values based on the measured surface parameters. For smooth surfaces the texture deformation is essentially elastic whilst the rough surfaces behave plastically. Linearity between the normal approach and the surface roughness at any given load is established and is thereby in agreement with theoretical expectation.