Adhesion and friction in viscoelastic rough contacts

Controlling adhesion and friction in viscoelastic contacts is crucial in several application fields of modern engineering. In this study, we investigate the adhesive contact of rough profiles sliding past a viscoelastic half-plane. We solve the multiscale contact problem enforcing energy balance between internal stresses and adhesive works under virtual infinitesimal variations of the contact domain. Our findings indicate that the interplay between adhesion and viscoelasticity at the contact edges and in the bulk material is fostered by multiscale roughness, eventually leading to strongly increased contact area and friction at characteristic sliding velocities. Finally, we compare the frictional behavior of a sinusoidal indenter (single wavelength) with the rough case (multiscale), showing that adhesion-induced friction enhancement occurs in both cases.