Numerical modelling of contact heat transfer problem with work hardened rough surfaces

A numerical model of heat conduction in vacuum through contact between two rough bodies made of commercial-purity AD1 aluminium is developed. To this end, the elastic-plastic contact deformation problem is solved accounting strain hardening. A method for consideration of surface initial cold work hardening and indentation size effect (ISE) is provided. Plastic characteristics of surface micro-volumes of material were taken from indentation results. Numerical realisation of the model in ANSYS finite element software is considered. Fractal surface models of two levels of roughness were used. Introduction of the second level roughness (microroughness) to the model was found to have considerable effect on the real contact area only when ISE is taken into account. An attempt to compare simulation results with data obtained with Shlykov's semi-empirical model was made.