Computational homogenisation framework for soft elasto-hydrodynamic lubrication

The true frictional behaviour in fluid film lubrication between rigid and microscopically rough surfaces undergoing finite deformation is still an open question in many practical applications. A direct solution approach via the Finite Element Method (FEM) is prohibitive due to high computational costs.
Within this work a coupled micro-macro analysis is proposed in terms of an efficient two-phase micro mechanical test by making use of the FEM on both scales. This homogenisation framework is exact to within a separation of scales assumption. The macroscopic interface fluid flux is identified from a lubrication analysis performed on the deformed configuration of a representative surface element. Parameter studies show a strong influence of both roughness and surface deformation on the macroscopic response for isotropic and anisotropic microstructures.