Hard-particle models assume that the collision between rigid bodies is
instantaneous and they propose algebraic equations for the jumps in the
motions of the rigid bodies based on an assumed functional form for the
impulsive force acting during the collision process. These hard-particle
models have the advantage that they are significantly less computationally
expensive than soft-particle models. Moreover, they are sufficiently accurate
for some applications and can also be used for preliminary analysis of
complicated processes with large numbers of particle interactions. Here,
a simple three parameter hard-particle collision model is developed which
predicts a smooth transition from normal collisions with no slip to oblique
collisions with full slip. This model automatically satisfies a number of
physical restrictions on the impulsive force. An additional physical restriction
on non-negative energy dissipation places nontrivial restrictions on the
model parameters. Examples show the importance of improved modeling
of the transition region from normal to oblique collisions with full slip.
Keywords
coefficient of restitution, collision, friction,
hard-particle, rigid bodies, spheres
