In this paper we report measurements of collisional properties of spheres using high-speed video analysis. These results agree with a simple collision operator. We study the size and velocity dependences of the coefficient of restitution in the normal direction. The experimental data are compared with the relevant models of energy dissipation and show the existence of two dissipation regimes. For large impact velocities a plastic deformation model is in good agreement with our measurements, while for smaller velocities a model of viscoelastic dissipation gives qualitative agreement.

• Received 30 May 1997

DOI:https://doi.org/10.1103/PhysRevE.56.5717