Thermal Contact Resistance of Nonconforming Rough Surfaces, Part 1: Contact Mechanics Model

A new analytical model for spherical rough contacts, in the form of a set of relationships, is developed and solved numerically. It is shown that the maximum contact pressure is the parameter that specifies the contact pressure distribution. Simple correlations for calculating the maximum contact pressure and the radius of the macrocontact area as functions of the nondimensional parameters are proposed. A relationship for pressure distributions is derived where the load is higher than the critical load. A general pressure distribution is developed that covers the entire range of spherical contacts from the smooth Hertzian to the conforming rough contact. Finally, a criterion is derived to identify flat surfaces where the surface curvature has negligible effect on the contact pressure.