Optimization of steel-UHMWPE multilayer armour under ballistic impact: Experiments and Simulations

Abstract

The ballistic performance of lightweight multilayer Steel-UHMWPE armour has been evaluated under high velocity impact using experiments and numerical simulations by optimising the thickness of steel and UHMWPE. Ballistics tests were performed on armour grade steel against 7.62×39 mm projectile travelling at 715 ± 15 m/s by varying the thickness of armour-grade steel between 3.0 to 5.0 mm to accomplish reduction of areal density. The ballistic results show that armour steel thickness 5.0 mm having areal density 39.3 kg/m2 can stop the projectile and can be used as monolithic armour. However, combining thinner steel plate with UHMWPE layers can potentially reduce the overall areal density while maintaining protection against 7.62×39 mm projectiles. To optimize the thickness of a multilayer steel-UHMWPE armour panel, numerical simulations were conducted using LS-DYNA. By varying the thicknesses of both the front steel plate and the backed UHMWPE layers in simulations, it was possible to identify optimal configurations that maximize protection while minimizing the weight. Two multilayer panels, namely, 4.0 mm thick steel backed by 5 mm thick UHMWPE and 3.0 mm thick steel backed by 7 mm UHMWPE were fabricated and tested for ballistic performance. Both the panels were able to provide protection against 7.62×39 mm projectile thereby reducing the areal density considerably by 22.7 % for 3 mm steel backed by 7 mm UHMWPE and by 7.6 % for 4 mm steel backed by 5 mm UHMWPE in comparison to monolithic layer of 5 mm thick steel. This optimization approach demonstrates the potential for significant weight reduction in multilayer armour steel-UHMWPE without compromising protection.