Transition from static to kinetic friction: Insights from a 2D model

Jørgen Trømborg (1) , Julien Scheibert (1, 2) , David Skålid Amundsen (1) , Kjetil Thøgersen (1) , Anders Malthe-Sørenssen (1)

1 PGP - Physics of Geological Processes [Oslo]
2 LTDS - Laboratoire de Tribologie et Dynamique des Systèmes

We describe a 2D spring-block model for the transition from static to kinetic friction at an elastic slider/rigid substrate interface obeying a minimalistic friction law (Amontons-Coulomb). By using realistic boundary conditions, a number of previously unexplained experimental results on precursory micro-slip fronts are successfully reproduced. From the analysis of the interfacial stresses, we derive a prediction for the evolution of the precursor length as a function of the applied loads, as well as an approximate relationship between microscopic and macroscopic friction coefficients. We show that the stress build-up due to both elastic loading and micro-slip-related relaxations depend only weakly on the underlying shear crack propagation dynamics. Conversely, crack speed depends strongly on both the instantaneous stresses and the friction coefficients, through a non-trivial scaling parameter.

Mots clés: static friction; kinetic friction; Coulomb friction; precursors; spring-block model; micro-slip; shear crack; dynamics; stress

Domaines: Mécanique des solides [physics.class-ph]; Mécanique des solides [physics.class-ph]

Jørgen Trømborg, Julien Scheibert, David Skålid Amundsen, Kjetil Thøgersen, Anders Malthe-Sørenssen. Transition from static to kinetic friction: Insights from a 2D model. Physical Review Letters, 2011, 107, pp.074301. ⟨10.1103/PhysRevLett.107.074301⟩. ⟨hal-00593313v2⟩