Transition from static to dynamic macroscopic friction in the framework of the Frenkel-Kontorova model

A new generation of experiments on dry macroscopic friction has revealed that the transition from static to dynamic friction is essentially a spatially and temporally non-uniform process, initiated by a rupture-like detachment front. We show the suitability of the Frenkel-Kontorova model for describing this transition. The model predicts the existence of two types of detachment fronts, explaining both the variability and abrupt change of velocity observed in experiments. The quantitative relation obtained between the velocity of the detachment front and the ratio of shear to normal stress is consistent with experiments. The model provides relations between kinematic and dynamic parameters of the transition process. (C) 2012 Elsevier Ltd. All rights reserved.