Molecular Dynamics Simulations of Rough Contact With Fractal and Statistical Surface Generation

Many studies on the contact of tribo-surfaces with nanoscale roughness adopt simplified deterministic surface topographies, which lend themselves to analytical solutions for the contact forces. More elaborate approaches that use, for example, fractal formulations are inherently more difficult to analyze but are increasingly used in tribological research. In this paper, molecular dynamics is used to simulate the three-dimensional contact between atomically rough surfaces of fcc-Nickel. Two methods are used to generate the surface roughness: fractals and a statistical approach utilizing spherical asperities. The tribo-surfaces are compressed with normal pressure and the results are compared for each method of rough surface representation. The two methods yield very similar results for the case of isotropic, Gaussian roughness.