Cracklike Dynamics at the Onset of Frictional Sliding

TL;DR

This paper introduces a new elasto-plastic friction model with interfacial stiffness, revealing transient cracklike fronts and a velocity gap in rupture dynamics, advancing understanding of frictional sliding behavior.

Contribution

It presents a novel friction model incorporating interfacial stiffness, demonstrating the existence of cracklike fronts and a velocity gap in rupture velocities.

Findings

Transient cracklike fronts are independent of sound speed.

A new velocity scale and a 'forbidden gap' of rupture velocities are identified.

Interfacial stiffness significantly influences rupture dynamics.

Abstract

We propose an elasto-plastic inspired friction model which incorporates interfacial stiffness. Steady state sliding friction is characterized by a generic nonmonotonic behavior, including both velocity weakening and strengthening branches. In 1D and upon the application of sideway loading, we demonstrate the existence of transient cracklike fronts whose velocity is independent of sound speed, which we propose to be analogous to the recently discovered slow interfacial rupture fronts. Most importantly, the properties of these transient inhomogeneously loaded fronts are determined by steady state front solutions at the {\em minimum} of the sliding friction law, implying the existence of a new velocity scale and a "forbidden gap" of rupture velocities. We highlight the role played by interfacial stiffness and supplement our analysis with 2D scaling arguments.