Memory effects in friction: the role of sliding heterogeneities

We report on memory effects involved in the unsteady-state frictional response of a contact interface between silicone rubber and spherical glass probe when it is perturbed by changes orientation driving motion or velocity steps. From measurements displacement fields at interface, we show that observed can be accounted for non-uniform distribution sliding within interface. As consequence these effects, friction force may no longer aligned with respect to trajectory. In addition, stick–slip motions purely geometrical origin are also evidenced. These observations adequately model takes into account heterogeneous displacements area. When dependence stress incorporated this model, regimes induced steps described. The good agreement experiments outlines role space heterogeneities soft matter friction.