LONG-ROD PENETRATION INTO TARGETS OF FINITE THICKNESS AT NORMAL IMPACT

In this paper, a theory for one-dimensional penetration of long-rods into targets of finite thickness (plates) is developed. The target is defined as a ''finite'' mass that resides within the bulk of the target so that an equation of motion for the target mass can be constructed. This, together with an equation of motion for the penetrator and erosion equations for the two masses, provides a penetration solution for the finite-thickness target problem. The axial extent of the target mass is simply the thickness of the plate. Results provide expected penetration rates into plate targets, as well as unpenetrated target thickness (plug or spall) and residual penetator length, mass, and velocity. Good agreement was found between the theory, hydrocode results and experimental data. Also, the formulation becomes hydrodynamic penetration in appropriate limits and therefore encompasses jet penetration of these targets as well.