On the role of local contact dynamics in the macroscopical frictional behavior

This paper presents the results of a 2D non-linear finite element analysis under large transformations of the onset and evolution of sliding between two isotropic elastic bodies separated by a frictional interface. The aim is to investigate in deep the trigger of the dynamic rupture at the interface, which preludes and goes with the sliding, and its effect on the macroscopic frictional stick-slip behaviour of the system. The analysis is focused on the energy flows associated to the interface phenomena observed during the onset of the sliding (micro-slips, precursors and macro-slips), accounting for the frictional properties and the inertial and elastic properties of the system. The results depict the frictional behaviour of a mechanical system as the outcome of a complex interaction between the local dynamics at the frictional interface and the global dynamics of the system.