Mixed elastohydrodynamic lubrication contact of piezoelectric materials with different Gaussian rough surfaces

The mixed elastohydrodynamic lubrication (EHL) behavior of a smooth, rigid, insulating cylindrical indenter in contact with transversely isotropic piezoelectric half-planes possessing Gaussian-distributed surface roughness is analyzed. Three distinct surface topographies are considered: longitudinally oriented, isotropic, and transversely oriented. The lubricant is assumed to exhibit non-Newtonian flow characteristics, and its density and viscosity are modeled to be pressure-dependent. A modified Reynolds equation, incorporating both pressure and shear flow factors, is utilized to compute the hydrodynamic pressure distribution within the lubricating film. An iterative computational scheme is developed for the coupled resolution of the modified Reynolds equation, flow rheology equations, asperity contact pressure equation, load balance equation, and film thickness equation. Parametric investigations are conducted to examine the influence of the total normal load, entrainment velocity, hydrodynamic roughness parameter, slide-to-roll ratio, contact roughness parameter, and surface pattern parameter on the film thickness, asperity contact pressure, and fluid hydrodynamic pressure. The results obtained may provide valuable insights for mitigating surface degradation at piezoelectric contact interfaces and enhancing the operational reliability of associated electromechanical systems.