Homogenized penetration calculations

Abstract

A model was developed which describes the penetration of a target composed of multiple discrete elements in terms of the penetration of an equivalent single-element target of identical thickness. To achieve this aim, the effective density and target resistance terms for the equivalent target have been homogenized from the densities and target resistances of the individual discrete elements composing the original target. Though the current model may be employed to treat a target's internal air gaps in the homogenization process, the current model does nothing special to address target considerations, such as obliquity, confinement, length-to-diameter (L/D) effects, etc. Rather, the model was intentionally restricted to flat-plate-type target elements being impacted at normal incidence, to focus upon the homogenization technique itself. To avoid the need to transform the shape or velocities of the bodies in question, only techniques which strictly preserved length and time dimensions were considered. Several homogenization schemes were examined and compared to the corresponding multi-element penetration calculation. It was determined that a straightforward volume averaging of target properties is usually not sufficient to effectively simulate a multi-element target. Other techniques presented here seem to do a better job at predicting residual penetrator length and velocity, respectively.