Particle based modeling approaches, such as the discrete element method (DEM) and cellular automata (CA) require the definition of accurate contact (collision) models. An essential parameter within these models is the coefficient of restitution (COR), which mathematically defines the ratio of post-collision to pre-collision relative velocity during the collision of two materials. This work studies COR for particle-boundary type collisions through detailed experimental investigations of falling spheres colliding with thin stationary plates over a range of impact velocities. The video shows an advanced lighting contrast scheme to capture impact time.

(1) Marinack Jr., M.C., Cosio, B., DellaCorte, C., Higgs III, C.F., 2013, "Experimental Investigations on the Coefficient of Restitution of Prestressed and Non-prestressed NITINOL 60," STLE Annual Meeting and Exhibition 2013, Detroit, MI.

(2) Marinack Jr., M.C., Musgrave, R.E., Higgs III, C.F., 2012, "Experimental Investigations on the Coefficient of Restitution of Single Particles," Tribology Transactions, Accepted for Publication.

(3) Marinack Jr., M.C., Dougherty, P.S.M., Higgs III, C.F., 2012, "Single Particle Interaction Properties: Investigations on the Coefficient of Restitution and Coefficient of Friction," Proceedings of the ASME/STLE International Joint Tribology Conference 2012, Denver, CO.

(4) Marinack Jr., M.C., Gaudio, B.G., Musgrave, R.E., Rizzo, C.E., Lovell, M., Higgs III, C.F., 2010, "Coefficient of Restitution Testing: Explicit Finite Element Modeling and Experiments," Proceedings of the ASME/STLE International Joint Tribology Conference 2010, San Francisco, CA.