Perforation equations for conical and ogival nose rigid projectiles into aluminum target plates

We developed closed-form perforation equations for rigid, conical and ogival nose projectiles that perforate aluminum target plates at normal impact. An existing cylindrical, cavity-expansion model that was experimentally verified with perforation data into 5083-H131 aluminum armor plates was used as the starting point for the development of the perforation equations. We identified a small parameter in those perforation equations, performed power-series expansions, and obtained closed-form, accurate perforation equations for the ballistic-limit and residual velocities. The closed-form, perforation equations are shown to be very accurate when compared with existing data for 6061-T651 and 5083-H131 aluminum target plates. Our perforation equations display clearly the dominant problem parameters.