An Integrated Computational and Experimental Approach for Selection of An Optimum Bullet Proof Armor

Abstract

During recent times, armouring industry has significantly flourished and has also seen large financial influx to develop and test new armours. Experimental set up for ballistic studies is costly followed by an experimental procedure, which is tardy and complex with a lot of sensors and cutting edge imaging technology. Also the experimental data which is mostly reliable does not capture all the required parameters. Substantial amount of research is being carried out to devise numerical and analytical models to accurately predict the ballistic performance of new armour designs and materials. This thesis presents a study of the ballistic performance of monolithic and multi layered target sheets against blunt and conical nose projectiles. Impact phenomenon including Adiabatic Shear Localization, Thermal Plastic Instabilities and High gradient of stresses have been modeled using FEM based explicit analysis solver. Appropriate strength, failure and shockwave models have been used both for brittle and ductile materials. Selected targets were tested against blunt and conical projectile moving in a velocity range of 200-500 . Result from impact simulations have been compared with the experimental data and analytical solution findings. By using different grades of metals and ceramic of varying strength and ductility in target shields, the combined effect of ductility and strength on energy dissipation and ballistic resistance has been investigated. Materials namely SiC, Al 7075 & Steel alloys including Weldox 460E & 4340 were investigated as eligible options for a ballistic target. Moreover, dominant failure modes in each case were observed and identified. It has been shown that FEM based simulations with carefully selected material and computational models produce quite comparable results. In the end, a comprehensive stud of seven different target configurations including monolithic and multi-layered option with different materials against a blunt projectile has been presented.