A Finite-Element-Based Contact Resistance Model for Rough Surfaces: Applied to a Bilayered Au/MWCNT Composite

A gold-coated multiwalled carbon nanotube composite (Au/MWCNT) is used as an electric contact material for low-current (<;100 mA) switching. It is shown that the surface of the composite presents a much higher roughness when compared to pure gold-coated surface. In previous studies, data from nanoindentation tests have been used to construct a finite-element (FE) contact model where the Au/MWCNT composite is modeled as a bilayered structure. In this paper, the FE model is adapted to the modified nanoindenation tests with a 1-mm-radius gold-coated stainless steel ball and to enable to predict the contact resistance. Measured rough surface data are used in the modeling. From the simulated contact area, the contact resistance is calculated using established theory. The influence of contact position on the contact resistance is investigated, and an average predicted contact resistance values are shown to be good approximation to measured data.