Investigation of high-velocity impact on integral armor using finite element method

Finite element analysis using DYNA3D has been performed to investigate the response of an integral armor under high-velocity impact. The analysis is based on actual experiments conducted in a gas gun set up. A 3-D model consisting of the various discrete layers of the armor has been developed and subjected to transient dynamic loading. The geometry and boundary conditions are all pertinent to the experiment. The projectile is blunt ended and is made from a hardened 4340 steel rod. The integral armor is a 305×305×46 mm3 plate with multi-component layers of AD-90 ceramic, EPDM rubber, S2-glass/Vinyl ester and phenolic composites. V50 velocity for a fragment-simulating projectile (FSP) has been considered, and the corresponding responses have been investigated to assess the failure of the armor at the ballistic limit. The analyses also provided information regarding the extent of the damage zone in the neighborhood of the bullet. The correlation with the experimentally observed damage zone was in good agreement with the FE analysis. Stress distributions through the thickness have been determined and maximum values were found to occur at the ceramic layer. From the delamination point of view the two interfaces across the rubber layer were found to be most critical. Interlaminar tensile and shear stress distributions have also been examined, and their contributions to the failure of the armor have been discussed.