Dynamic investigation of hard viscoelastic materials by ball bouncing experiments

Abstract

An experimental device is described for studying the behaviour of a material subjected to the impact of a rigid spherical indentor, in the temperature range −25 to +90° C. For each experimental run performed on a quasi-semi-infinitely hard viscoelastic PVC material, the coefficient of restitution, the duration of impact and maximum penetration were measured. From a series of runs performed with different impact velocities, the effective damping was computed as well as the dynamic hardness. Comparison with a periodic test method proved to be fairly good. In particular the same results on specific losses were obtained by both methods, as long as the impact kinetic energy did not exceed 170 mJ. Furthermore an estimate of the storageE modulus can be made from the contact time. As this paper deals with linear viscoelasticity, the specific deformation energies involved are not too high.