THE RIGID SPHERICAL PROJECTILES REBOUND T EST - A SIMPLE METHOD TO DETERMINE BOTH THE SUPERFICIAL PROPERTIES AND RHEOLOGICAL BEHAVIOR OF A NATURAL-RUBBER

We have shown in a recent paper (Barquins and Charmet, 1994) that a si mple energy balance allows us to predict the rebound height of a rigid and polished ball, made of alumina, colliding with a horizontal, plan e, smooth and cleaned surface of a natural rubber sample. In addition, we have shown that there is a critical drop height below which the ba ll sticks and does not bounce at all. The simple energy balance propos ed gave a correct prediction of the observed rebound height. In this p aper, numerous and new experiments with the aid of polished stainless steel balls and various projectiles providing a circular area of conta ct, were carried out to better confirm the proposed model and it is de monstrated that these rebound experiments allow one to determine accur ately the superficial properties of the rubber sample and its viscoela stic behaviour through the experimental determination of the exponent n of the general equation of the adherence of elastomers proposed by M augis and Barquins in 1978.