A multiphysics theory for the static contact of deformable conductors with fractal rough surfaces

Abstract

In the present paper we are proposing a multifield and multiscale theory leading to derivations of electric and thermal conductivities for the interface between two rough surfaces in contact activated by mechanical load and electric current pulses. At the macroscale the proposed model involves multifield coupling of conduction and induction currents with heat conduction induced by Joule heating. The structural mechanics of the conducting materials are also considered. At the mesoscale and microscale the associated model contains an asperity based comprehensive model that leads to homogenized macro scale properties for the interface boundary. The mechanical pressure and the repulsion effect from electric current through the micro-contacts are accounted for as well. Finally, the entire framework is applied to an actual conductor configuration of hollow cylinders under compression and a high current pulse to demonstrate the feasibility of the entire approach. In addition to providing typical results for all selected fields present during the experiment and the simulation, we also provide a comparison between the experimentally acquired resistance histories with the numerically derived ones to address validation aspects of the general multiphysics contact theory.