A Comment on the Prediction of Metallic Plate Penetration by Fragment-Simulating Projectiles

Abstract

Metallic targets impacted by blunt-nosed projectiles typically fail via shear plugging. Various models exist that predict the onset of this failure threshold, which can be used to determine the ballistic limit velocity for a particular combination of projectiles and targets. In a previous study, nine existing penetration models were evaluated for their ability to predict the ballistic limit velocity of monolithic titanium alloy, aluminum alloy, and steel plates under small caliber fragment-simulating projectile impact. In a second study, a series of changes to these nine models were proposed, typically based on empirical adjustments, reformulation of the target strength dependency, or a combination of both. The effectiveness of these changes in improving the predictive capabilities of these nine models was assessed by comparing model predictions against more than 650 ballistic limit measurements. In this paper, we compare the ballistic limit velocities predicted by these nine models against ballistic limit measurements not included in the original 650 + dataset that guided the development of model improvements. It was found that the nine penetration models considered in these two previous studies are most suited for applications in which target plates can be considered “hard” or “high-strength.” In situations where target plates are made of “softer” materials, the predictive ability of these nine models was less than desirable.