Multiscale numerical optimisation of hybrid metal/nonwoven shields for ballistic protection

Abstract

This research presents a detailed numerical study of the ballistic performance of lightweight hybrid metal/nonwoven shields for automotive applications. Several configurations, including different number of nonwoven fabrics, were analysed to find the optimal design. Impact response of the nonwoven fabric was predicted by a multiscale numerical constitutive model able to capture its complex deformation and failure mechanisms: fibre straightening, realignment and disentanglement. Special attention was paid to the interaction between layers for different air gaps in the final energy absorption capacity of the shield, and detailed analysis of the different sequences of triggered failure modes was provided. The hybrid shield outperformed the previous configurations, resulting in an absorption capacity about twice the sum of the energies dissipated by the steel plates and the nonwovens individually. Furthermore, the hybrid shield increased the energy absorption capacity of the baseline steel plates by a factor over 8, with an almost negligible increment of areal weight of 5.5%, giving the possibility to improve the ballistic performance of conventional automotive components without penalising the fuel consumption of the vehicle.

Study of dynamic compressive responses of ultra‐high molecular weight polyethylene felt impregnated with shear thickening fluid

“…It is observed that for neat felt, the entire longitudinal stress wave generated by the projectile impact passes through the felt and gets reflected at its junction points on account of lossy, frictional, and stick–slip mechanism 16 . This wave induces fiber slippage and ultimately felt gets dispersed at a higher strain rate 41 . However, less yarn slippage is observed in STF impregnated felt.…”

“…16 This wave induces fiber slippage and ultimately felt gets dispersed at a higher strain rate. 41 However, less yarn slippage is observed in STF impregnated felt. The inter yarn STF acts as a bridging matrix and helps transfer the load collectively with fiber by increasing friction between the yarn.…”

Design and bulletproof performance investigation on the ceramic/metal laminated composite

“…López-Puente et al 6 demonstrated that there is an optimum adhesive layer thickness of alumina/aluminum armors for the best ballistic performance of the lightweight protection. Vila-Ortega et al 7 implemented the multi-scale optimization of hybrid metal/ nonwoven shields for ballistic protection.…”

Dynamic Tensile Testing of Needle-Punched Nonwoven Fabrics

“…Needle-punched nonwoven fabrics present a lower stiffness and strength (as well as processing cost) than their woven counterparts, but possess a higher deformability and excellent ballistic performance against small calibres and shrapnel [4]. It is possible to find in the literature multiple applications for protective barriers based on nonwoven fabrics for soft body armour and the transport industry [5][6][7][8][9][10]; nevertheless, the biggest improvement in ballistic performance is obtained when nonwoven fabrics are combined with traditional barriers based on dry woven fabrics, as cushion layers, or metal plates with a negligible increment of the total areal weight of the target [4,[11][12][13]. It is possible to find detailed studies focused on the quasi-static response [14,15] and the ballistic performance of the material [10,[16][17][18][19]; nevertheless, there is still a lack of knowledge regarding the effect of high strain rates in its mechanical properties.…”