The measurement of particle rebound characteristics

Accurate measurements have been made of the rebound behaviour of 5 mm aluminium oxide spheres impacting a thick soda–lime glass anvil (fully elastic response) and an aluminium alloy anvil (involving some plastic deformation). Speed, angle and rotation before and after impact have been measured with a strobe and single-frame digital camera, for a range of impact angles from normal to very near glancing. High levels of reproducibility and precision have been achieved by careful attention to all aspects of the measurement, including the mechanical and optical systems, illumination, electronic control, and computer-based image measurement. Rebound parameters from the elastic and plastic impacts are analysed and compared in the context of the numerical work of Maw et al. for near-normal angles when sticking, micro-slip and tangential compliance are the major factors, and of rigid body sliding for more oblique angles.