On the constant deceleration assumption: A numerical investigation of projectile penetration into semi-infinite concrete and aluminum targets

In this study, the deceleration of non-deforming projectiles with different nose shapes during penetration into semi-infinite concrete and aluminum targets was investigated using hydrocode simulations. The aim of the work was to review the assumption of constant deceleration, which underlies several empirical or semi-analytical models, and to provide a foundation for future models. The results of the performed simulations show that the deceleration of projectiles fundamentally varies as a function of the instantaneous velocity and the impact velocity and is thus generally not constant. This is particularly true for concrete and is therefore likely to apply to similar geomaterials. In the case of aluminum, the assumption of constant deceleration is, to some extent, reasonable within specific velocity regimes.