Elsa Bayart (ENS Lyon) - Friction and Fracture: Geophysics in the lab

Friction and Fracture: Geophysics in the lab

What happens at the interface between two solid bodies in contact when they start sliding? This problem has important implications to various fields such as engineering, where the challenge is to control friction, or earthquake dynamics, where prediction of earthquakes occurrence and magnitude is crucial.
A frictional interface is composed of an ensemble of discrete contacts that resist to shear. Sliding motion is mediated by the propagation of an interfacial rupture, breaking the micro-contacts, that has been shown to be a true shear crack. Through laboratory experiments, we study how interfacial disorder affects the onset of sliding of two solid bodies in contact. We show that disorder can drastically modify the macroscopic dynamics of the interface via the modification of the fracture initiation or propagation processes. The impact of our results on earthquakes dynamics will be discussed.