In this project I address the questions of how the frictional forcedepend on the sliding velocity. Can asperity creep give a velocityweakening effect on the dynamic coefficient of friction for low sliding velocities, and a transition between static and dynamic friction?
In this project I will study a physical system where ablock is pushed by a piston on a rough base. I will develop adiscrete element method with next-nearest neighbor interactions, andinteractions between the slider and the base. I willsimulate sliding at different sliding velocities and study theresulting friction laws of the relation between the sliding velocityand the dynamic coefficient of friction. Two different models for adhesion is also introduced to study the effect of adhesion on the dynamic coefficient of friction with and without time dependenceof the real area of contact.