A Computational Study of Nano-Scale Contact and Friction

A simulation is undertaken to consider the effects of the scale of surface roughness on elastic contact and friction. In the simulation, a cylindrical rigid indenter of a prescribed profile is brought into contact with an elastic half-space. Interaction between the indenter and the half-space occurs through an assumed surface potential derived from the 6-12 Lennard-Jones intermolecular potential. The hypothesis under investigation is that by assuming the frictional stress is proportional to the magnitude of the normal stress, irrespective of sign, one can account for the enhanced frictional stress at the nano-scale vs. the micro-scale that has been observed experimentally. Results of the simulations indicate qualitative agreement with recent experimental findings.