A penetration model for semi-infinite ultra-high molecular weight polyethylene composite

Ultra-high molecular weight polyethylene (UHMW-PE) composite has been shown to be an effective material for ballistic protection against blunt penetrators [1]. The material exhibits multiple stages of penetration, typically characterised by an initial local penetration phase followed by large bulge deformation of the back face [2]. The location at which transition occurs between the localised penetration stage and non-localised bulging stage is an important property of UHMW-PE composite armour. However, the conditions required to induce transition are poorly understood with a range of different mechanisms proposed to explain the behaviour [2,3], none of which can be used to predict the transition location within the target.