On the friction effect in the perforation of metallic plates by rigid projectiles

In this work we analyze the effect of friction on the shank of a rigid sharp-nosed projectile as it perforates a metallic plate. In order to account for this retarding force we use a velocity-dependent friction coefficient which is calibrated through several sets of perforation experiments. It turns out that this coefficient has non-vanishing values only for low sliding velocities. Thus, the friction's contribution is apparent only when the impact velocity is close to the ballistic limit velocity of the projectile/plate pair.