Normal load, slip rate and roughness influence on the PMMA dynamics of sliding 2. Characterisation of the stick-slip phenomenon

We performed an extensive study on PMMA-PMMA dry friction. For a wide ran of normal pressures, slip rates and grades of roughness of sliding surfaces we focused on the detailed characterisation of the stick-slip motion. With an original experimental device associated with a high speed data acquisition system, we measured six parameters: the distance and the duration of slip, the maximum velocity during slip motion, the relative displacement and/or deformation during the stick phase and the duration of this phase, and the number of events per millimeter of displacement. We observed that all parameters are strongly influenced by normal pressure and do not vary according to the slip rate apart from the duration of stick which was mostly influenced by slip rate. Furthermore, apart from the duration of slip, all parameters are influenced by roughness. (C) 1998 Elsevier Science S.A.