Influence of CNT and graphene on the mechanical and ballistic performance of soft body armor

Currently, bullet-proof vests (soft or flexible composite armor used for body protection) are usually made from high stiffness and toughness, woven or laminated, polymeric fibers stacked in a number of layers. Upon impact of the striking bullet, the fabric material absorbs the energy by stretching of the fibers allowing the dispersion of the load over a large area throughout the material. This process slows down the bullet and ultimately stops it from penetrating into the wearers body. In case of polymer matrix composites (PMCs), the ability of a fiber to deform is severely restricted due to the presence of surrounding resin, and therefore, the energy absorption capacity can reduced. The main failure mechanisms in PMCs under ballistic impact are straining of fiber and fracture, delamination and shear deformation in the resin matrix. Carbon nanotube (CNT) is an ideal candidate material for bulletproof vests due to its unique combination of exceptionally high elastic modulus and high yield strain. A Young's modulus of about 1000 GPa, strength ranging between 13-53 GPa, and strain at tensile failure predicted to be as high as 16% typically characterize CNTs. Given that the specific gravity of CNT is about 1.4 g/cm3, estimates of the ballistic performance parameter can range between 2708 m/s and 4326 m/s. If one compares these values with those for other fibers suitable for ballistic applications, the enormous potential of CNTs as a candidate material for bullet-proof armor system is quite evident. Recently CNTs and graphene have been incorporated into soft body armor vests with the aim of improving their ballistic performance. The results show that carbon-based nanomaterials are promising materials for the design of the new generation of soft body armor. Therefore, the aim of this work is to develop novel ballistic soft body armor composites by incorporating multiwall CNTs and graphene into the armor fabrics. Mechanical characterization of the developed composite will be carried out along with assembling the modified fabrics for ballistic testing to unravel the improvement attained from the modification.