Effect of Mass of Drop-hammer in Impact Punching with PVA Gel as Working Medium

Abstract

We experimentally investigated the effect of the mass of a drop hammer in impact punching with polyvinyl alcohol (PVA) gel as the working medium. There is an optimal mass of the drop hammer. For constant initial energy, if the mass of the drop hammer is small, the impulse (change in momentum) becomes small, and punching cannot be accomplished. On the other hand, if the mass of the drop hammer is large, the speed of the pressurizing ram will be small for the same kinetic energy, the flow pressure of the PVA gel will not be sufficiently raised, and again, punching cannot be accomplished.