Experimental and numerical evaluation of the perforation resistance of multi-layered alumina/aramid fiber ballistic shield impacted by an armor piercing projectile

Multilayered Armor System is an efficient protection which combines a ceramic front layer and ductile backing usually made by a metal or a composite material. Numerical models are an effective tool to design ballistic protections. Such models may be used as virtual tests, strongly reducing the efforts for experimental testing. Moreover, numerical models can be used for optimization of protections. However, the correct definition of such models is not straightforward and requires strong expertise both in material and numerical modelling. Fragmentation of ceramic cannot be correctly simulated by the Finite Element method, which is commonly used in the literature. Indeed, the Finite Element method requires the implementation of element erosion which is introduced errors due to mass and energy loss. To solve this issue, the aim of this work is to develop and validate a Finite Element coupled to Smoothed Particle Hydrodynamics model for the simulation of ballistic impact against a Multilayered Armor System. Experimental tests were performed to obtain the ballistic curve for the 7.62 × 51 P80 bullet on a full Multilayered Armor System (Kevlar®29/epoxy cover, alumina tiles and Kevlar®29/epoxy backing), obtained using a one-stage vacuum infusion. Consequently, the numerical model was validated showing good agreement with the experimental results.