Yarn-Level modelling of woven and unidirectional thermoplastic composite materials under ballistic IMPACT

Abstract

Composite materials made of high-strength fibres (for example, aramid or UHMWPE) are extensively used in such protective structures as bulletproof vests, helmets, etc. Many researchers have carried out numerical simulations of ballistic impact on composite laminates applying continuum, multiscale and mesoscale approaches. The continuum approach requires a little computational time but cannot catch all features of composite panel or fabric plies behaviour during high-velocity impact. Thus, using the mesoscale and multiscale models has recently been increased. In this paper, mesoscale approach was used to simulate a 6.35 mm steel ball impact on two types of hot-pressed thermoplastic composites with LS-DYNA finite-element code. The first type of the composite panel is made of aramid fabric KV110P (plane weave structure) with LDPE matrix. The second one was Dyneema® HB80 UD laminate. The proposed models of the real-sized panels were based on the combination of shell (for yarns) and solid (for resin) elements with common nodes to reduce an overall number of contacts and CPU time. The yarn-level modelling allowed using simple material models and fracture criteria. The models reflect the main failure modes in the real panels including the fracture of fibres, delamination, fabric/matrix debonding, yarns pull-out, etc. The experimentally obtained ballistic curves were used to validate results of the numerical simulations.