Frictional shear cracks

TL;DR

This paper models crack propagation along interfaces between dissimilar materials using a viscous friction law, linking static friction to Griffith threshold and analyzing how shear stress influences crack velocity and dissipation.

Contribution

It introduces a model for interface crack propagation incorporating viscous friction, connecting static friction to Griffith threshold and analyzing energy dissipation.

Findings

Crack velocity depends on applied shear stress.

Main dissipation occurs in the macroscopic region due to interface friction.

Results relate to recent experimental observations.

Abstract

We discuss crack propagation along the interface between two dissimilar materials. The crack edge separates two states of the interface, ``stick'' and ``slip''. In the slip region we assume that the shear stress is proportional to the sliding velocity, i.e. the linear viscous friction law. In this picture the static friction appears as the Griffith threshold for crack propagation. We calculate the crack velocity as a function of the applied shear stress and find that the main dissipation comes from the macroscopic region and is mainly due to the friction at the interface. The relevance of our results to recent experiments, Baumberger et al, Phys. Rev. Lett. 88, 075509 (2002), is discussed.