Friction is Fracture: Fracture Processes Drive Frictional Motion
Event details
| Date | 24.01.2014 |
| Hour | 11:00 › 12:00 |
| Speaker |
Prof. Jay Fineberg Bio: Jay is interested in many different (rather loosely related topics) whose main common denominator is that they are nonlinear phenomena, that he would like to understand. |
| Location | |
| Category | Conferences - Seminars |
Frictional processes entail the rupture of the ensemble of discrete contacts defining a frictional interface. There are a variety of views on how to best describe the onset of dry frictional motion. These range from modeling friction with a single degree of freedom, a “friction coefficient”, to theoretical treatments employing dynamic fracture to account for spatial and temporal dynamics along the interface. We perform simultaneous high-speed measurements of the real contact area and the strain fields in the region surrounding propagating rupture tips. We show that, along dry (nominally flat) rough interfaces, the transition from "static" to "dynamic" friction is quantitatively described by classical singular solutions for the motion of a rapid shear crack. We find that these singular solutions, originally derived to describe brittle fracture, are in excellent agreement with the experiments for slow propagation while some significant discrepancies arise as the rupture velocity, Cf, approaches the Rayleigh wave speed, Cr. In addition, the energy dissipated in the fracture of the contacts remains nearly constant throughout the entire range of "Cf less than Cr", while the size of the dissipative zone undergoes a Lorentz-like contraction as Cf approaches Cr. This coupling between friction and fracture is critical to our fundamental understanding of frictional motion and related processes, such as earthquake dynamics.
Practical information
- General public
- Free
Organizer
- Jean-François Molinari (LSMS, Computational Solid Mechanics Laboratory)
Contact
- Mathilde Radiguet, Birgitte Seem