On the viscous dissipation caused by randomly rough indenters in smooth sliding motion

The viscous dissipation between rigid, randomly rough indenters and linearly elastic counter bodies sliding past them is investigated using Green's function molecular dynamics. The study encompasses a variety of models differing in the height spectra properties of the rigid indenter, in the viscoelasticity of the elastomer, and in their interaction. All systems reveal the expected damping linear in sliding velocity v at small v and a pronounced maximum at intermediate v. Persson's theory of rubber friction, which is adopted to the studied model systems, reflects all observed trends. However, close quantitative agreement is only found up to intermediate sliding velocities. Relative errors in the friction force become significant once the contact area is substantially reduced by sliding.

Automated summary

The study investigated the viscous dissipation between rigid, randomly rough indenters and linearly elastic counter bodies sliding past them using Green's function molecular dynamics. Different models showed expected damping linear in sliding velocity at small velocities and a pronounced maximum at intermediate velocities. Persson's theory of rubber friction reflected all observed trends, but closer quantitative agreement was only found up to intermediate sliding velocities, with significant relative errors in the friction force once the contact area was substantially reduced by sliding.