Accounting for the elastic properties of viscoplastic lubricant between coaxial rotating cylinders

This paper presents a solution of the boundary-value problem of the stress-strain state of a friction unit placed in the gap between rigid rotating cylinders. It is assumed that the two-layer incompressible material of these unit has elastic, viscous, and plastic properties and different values of the elastic moduli, stress limit, and viscosity. The conditions of the occurrence of viscoplastic flow, motion of the elastoplastic boundary in a deformable medium, and interaction of the latter with the contact boundary of the materials were determined. Limiting values of the characteristic rotation parameters at which the damping layer of the friction unit is not deformed plastically are given. The velocity and stress fields for acceleration and deceleration of the lubricant flow are calculated.