On the design of kinetic energy non-lethal projectile based on the dynamic characterization of polymer foams

Abstract

Anti-personnel non-lethal weapons (NLWs) dissuade uncivil, suspect, or hazardous behavior while posing a low risk of permanent or fatal injury. In conflict situations involving armed forces, such weapons serve to reduce collateral damage. The most commonly employed NLWs are kinetic energy non-lethal weapons (KENLWs), which include firing a deformable, breakable, or rigid projectile without producing injuries that require more than basic first aid or leave permanent lesions. However, actual cases show that these projectiles can cause permanent harm or death, prompting an evaluation of their injury potential. Determining the composition and mechanical behavior of such projectiles is critical for predicting and ensuring their safe and efficient use. The main objective of the present article is to develop an assessment methodology of non-lethal deformable projectiles, based on experimental and numerical investigation tools, using an in-house 40 mm kinetic energy non-lethal projectile (KENLP). Firstly, the mechanical behavior of the projectile's nose material, polyethylene-vinyl-acetate (PEVA) foam, under quasi-static and dynamic compression was characterized. Dynamic tests were conducted at low and high velocities using a drop-weight tower and a direct split Hopkinson pressure bar (DSHPB), respectively. The effect of strain rate on plateau stress and densification strain was investigated. Subsequently, the developed KENLPs were launched against an instrumented rigid wall (RW) at high velocity using a laboratory gas gun. Finally, finite element numerical simulations were performed.