Lubricated friction: insight into weakening mechanisms
| Quand ? |
Le 14/04/2016, de 10:45 à 12:00 |
|---|---|
| Où ? | Amphi C |
| Participants |
Elsa Bayart |
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The transition from static to sliding friction is mediated by the propagation of rapid interfacial ruptures through the solid contacts that form the frictional interface. Understanding of the dynamics of these ruptures is a challenge both to control the mechanical properties of solids and to describe the dynamics of earthquake ruptures. In dry friction, while propagating, these ruptures correspond to true shear cracks but also when they are spontaneously arrested along the interface. In lubricated friction, how the fluid acts to weaken the interface remains enigmatic. By using a fracture-mechanics-based framework, we show that the lubricant increases the dissipated energy during the rupture process. As a consequence, the residual stress is strongly reduced compared to a dry interface. We ask about the microscopic processes, at the contact level, responsible for this effect.