Independent friction-restitution modeling of collisions: application to planar sphere rebound on a massive surface

The most widely used impulse-based description of impact events expresses it in terms of the coefficient of restitution (normal and tangential) and friction. This model leads to significant variations of the coefficients of tangential restitution and friction with the impact angle. An alternative formulation is presented based on the idea that friction and restitution can be treated as 'mechanisms' operating simultaneously but independently throughout the impact. The resulting independent friction restitution closure describes the impact for both stick and slip regimes using the same set of 'constant' coefficients of restitution (normal and tangential) and friction. The model yields theoretical predictions in agreement with reported experimental data including several results considered as 'anomalous' in the literature.