Frictional interfaces are abundant in natural and man-made systems, and predicting their behavior still poses challenges of scientific and technological importance. Recent experimental discoveries have revealed rich spatio-temporal dynamics that precede the onset of sliding motion, and occur well below the nominal static friction coefficient. In this talk we will highlight novel features of frictional constitutive laws -- most notably a transition from velocity-weakening friction at small slip velocities to velocity-strengthening friction at higher velocities¹ -- and theoretically explore their implications on the stability and failure of frictional interfaces². We demonstrate the existence of new steadily propagating rupture modes and quantitatively study their spontaneous emergence via frictional instabilities, occurring independently of the nominal static friction level, typically well below it. Finally, we assess how material properties at high sliding velocities and residual stresses affect the global stability of frictional interfaces.

[1]   On the velocity-strengthening behavior of dry friction, arxiv:1308.1420

[2]   Instabilities at Frictional Interfaces: Creep Patches, Nucleation and Rupture Fronts, arxiv:1306.3658