Ballistic performance of Polycarbonate and Polymethyl methacrylate under normal and inclined dynamic impacts.

Polymeric materials have exceptional mechanical properties, making them attractive for automotive, aerospace, defence and buildings industries. The numerical analysis of translucent polymeric materials' ballistic performance is investigated to analyse the deflection and perforation performance at high impact velocities. Computational methods are exploited to predict the ballistic performance of thick targets and projectile damage, and the results are validated against published works. The 3D numerical analysis is conducted by simulating plates and projectiles' mechanical performance that controls the deflection and ricochet procedure. Impact damage analysis is undertaken on monolithic Polycarbonate (PC) and Polymethyl methacrylate (PMMA) targets under various impact velocities, projectile's core density with inclined 30 ∘ and normal 90 ∘ impact angle. The results are analysed in terms of failure performance, depth of penetration (DOP), penetration path (POP), and residual velocity. The numerical analysis is further developed to investigate the projectile's impact velocity effects on the DOP and its direction. The results showed that the DOP changes linearly with the impact velocity, where the POP is as yet nonlinear. Extended Drucker Prager Strength (EDP) material model with the failure criteria of principal stress and tensile pressure failure is used to simulate the brittle-ductile PMMA target's performance under dynamic impact. Shock Hugoniots equation of state with plastic strain failure is conducted to affect PC plates' tensile performance.

Investigation of Penetration Performance of Zr-based Amorphous Alloy Liner Compared with Copper.

Zr-based amorphous alloy is a new type of metastable energetic material, which has been exploringly used to design shaped charge (SC) liners by scholars of the military industry. In order to know well how the stand-off distance influences jet penetration performance of liners made by such energetic materials against metal targets, SC static explosion tests were conducted under the same initiation and target conditions but different stand-off distances compared with copper liners. Test results indicate that the jet depth of penetration (DOP) of Zr-based amorphous alloy liners firstly increases slowly and then decreases sharply as the stand-off becomes larger. The optimum stand-off distance is 3.5 times of charge diameter (CD) and the corresponding maximum DOP is about 2.68 CD against the 45# steel plate. The perforation area varies with the stand-off distance. It reaches the maximum when the stand-off is 3.5 CD and the corresponding perforation diameter is about 42mm, also the penetration hole is nearly circular. The jet DOP of Zr-based amorphous alloy liner is smaller than that of copper liner's while the perforation area is the opposite. The former DOP is about 55.7% of the latter and the former perforation area is about 2.8 times of latter when the stand-off distance is 3.5 CD.