Material behavior in plane polyurethane-polyurethane impact with velocities from 10 to 400 m/sec

Shock response of the rubber-like polyurethane (PU) has been studied in symmetrical plane/impact experiments in the impact velocity range 10 - 400 m/sec. The free surface velocity of the samples was measured by the laser velocity interferometer. It has been found that for a weak impact the step-like perturbation cannot penetrate into the polyurethane sample while the signal with the risetime of 1μsec and higher may propagate in the material with some steepening. The Poisson's ratio of PU estimated on the basis of the weak-impact data is close to 0.5. With the increase of the impact strength the PU shock response becomes more similar to that of a normal solid with Poisson's ratio 0.39.