Shape effects in hypervelocity impact on semi-infinite metallic targets

In this study, an existing penetration equation, which was originally designed to give the penetration depth of spherical projectiles at hypervelocity into semi-infinite metallic targets, was modified to give the penetration depths of rotationally symmetric ellipsoid shaped projectiles into semi-infinite targets. To that purpose, a shape factor was defined in order to be able to describe the ellipsoid shape with a single number. The shape factor corresponds to the l/d ratio of rod- or disk-like projectiles. It was shown, that existing penetration equations can be modified to account for the shape of the projectile by introducing a single factor fn. From the experimental and simulation data available in this study, n=0.45 was derived as a suitable exponent to describe the shape effect. In addition to the experiments numerical simulation was performed to enhance the data base and to show itʹs value for further investigations of the shape effect.