Inelastic contact behaviors of nanosized single-asperity and multi-asperity on α-Fe surface: Molecular dynamic simulations

Abstract

Contact surfaces are widely used in precision machines for transmitting force and torque, whose characteristics are crucial. The onset of plasticity during contact at microscale is different from macroscopic behavior. Taking α-Fe as the paradigm material, inelastic behaviors of nanosized single-asperity and multi-asperity contact on the α-Fe surface were investigated using molecular dynamics (MD) simulations. The results show that (i) the macroscopic single-asperity model limits to accurately describe the nano-sized contact behavior, especially the estimation of the onset plasticity, (ii) the offset distance can delay the onset plasticity, (iii) compared with the MD simulation, the Greenwood-Williamson (GW) elastic model has a higher estimation on the contact force, while the Chang-Etsion-Bogy (CEB) and other revised-CEB elastoplastic models underestimate the contact force.