Experimental study of the statistics of slipping events in solid friction

Abstract. The statistics of the stick-slip motion is studied in two experiments, where elasticity is distributed either on a surface or on a volume. The rough surface is realised by embedding steel spheres in an elastic substrate whereas the volume is constituted by several layers of rubber spheres. Both systems produce a complex dynamics characterized by power law with non-trivial exponents in the distribution of the amplitude of the slipping events and in the power spectra of the friction force time evolution. The dependence of the results on the system size is also studied.