2004/12/18 by Jan M. Skotheim, J. M. Skotheim, L. Mahadevan · 3 citations
Engineering · Physics and Astronomy · #Adhesion, Friction, and Surface Interactions #Gear and Bearing Dynamics Analysis #Tribology and Lubrication Engineering #cond-mat.soft
paper · pdf · doi:10.1063/1.1985467
61 pages, 20 figures, 2 tables, submitted to Physics of Fluids
arxiv created 2004/12/18 · openalex publication_date 2005/09/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the lubrication of fluid-immersed soft interfaces and show that elastic deformation couples tangential and normal forces and thus generates lift. We consider materials that deform easily, due to either geometry (e.g., a shell) or constitutive properties (e.g., a gel or a rubber), so that the effects of pressure and temperature on the fluid properties may be neglected. Four different system geometries are considered: a rigid cylinder moving parallel to a soft layer coating a rigid substrate; a soft cylinder moving parallel to a rigid substrate; a cylindrical shell moving parallel to a rigid substrate; and finally a cylindrical conforming journal bearing coated with a thin soft layer. In addition, for the particular case of a soft layer coating a rigid substrate, we consider both elastic and poroelastic material responses. For all these cases, we find the same generic behavior: there is an optimal combination of geometric and material parameters that maximizes the dimensionless normal force as a function of the softness parameter η=hydrodynamicpressure∕elasticstiffness=surfacedeflection∕gapthickness, which characterizes the fluid-induced deformation of the interface. The corresponding cases for a spherical slider are treated using scaling concepts.