A Predictive Non-Dimensional Scaling Law for the Plate Perforation of Several Aluminum Alloys by Fragment-Simulating Projectiles

An equation was previously-presented to predict the ballistic-limit velocity for the perforation of aluminum armor plates by fragment-simulating projectiles (FSP). The ballistic-limit equation was presented in terms of dimensionless parameters so that the geometric and material problem scales are identified. Previously published predictions and data for two different FSP projectile calibers (12.7 mm and 20 mm) and two different strength aluminum alloys show the scaling law to be accurate. In this paper we extend the same concept to several other alloys and show that this scaling law is predictive.

Analysis on Perforation of Ductile Metallic Plates by APM2 Bullets

By employing the theoretical model of a rigid sharp-nosed projectile perforating the ductile metallic target plate, the present paper re-analyzes the previously published experimental data of APM2 bullet and its hard steel core perforating aluminum armor plates and high-strength steel plates, respectively. Although the bullet deforms during the perforation, the test confirms that the hard steel core dominates in the perforation but the brass jacket, lead cap and end cap only have limited influence on the ballistics. Therein the perforation model of a rigid sharp-nosed projectile may be conducted to analyze the perforation of APM2 bullet. With increasing the thickness of ductile metallic target plate, the inertia effect of target will arise and obviously affect the terminal ballistics. The inertia effect of target must be considered in the scenario of thick target plate.

Dynamic Cylindrical Cavity Expansion of Compressible Strain-Hardening Materials

We developed models for the dynamic expansion of cylindrical cavities from zero initial radii for compressible, elastic-plastic, rate-independent materials with powerlaw strain-hardening. Results from cavity-expansion models were used to derive perforation models to predict residual velocities and ballistic limits for rigid, conicalnose projectiles perforating strain-hardening target plates. We compared the numerical results from models for incompressible and compressible materials to show the effect of compressibility. To verify the models, we also compared the model predictions of residual velocities and ballistic limits with the data from terminal-ballistic experiments with tungsten projectiles impacting 5083-H131 aluminum armor plates at normal incidence. Very good agreement was obtained for impact velocities between 200 and 1,200 m/s and 12.7, 50.8, and 76.2-mm thick targets.