Studies on ballistic evaluation of aramid laminated composites subjected to impact of projectiles

Abstract

Aramid fibers in the Kevlar®/ Twaron® family of fabrics consist of highly aligned newlinemacromolecules strongly bonded to one another resulting in excellent tenacity newlineand modulus thus making them ideal for armor materials which serve as a newlineprotective shield in a variety of systems such as helicopters, tanks, personal newlinecarriers and body armor. The understanding of the ballistic impact response of newlinepopularly used Twaron® / Kevlar® fabric based composite plates under impact of newlineordnance projectiles of different shape and size, particularly under the conditions newlinefor perforation is of paramount importance in the design of suitable light weight newlinearmor. The perforation behavior of aramid laminates made from different resin newlinesystems against fragment simulating projectile (FSP) or steel penetrator launched newlinefrom gas guns has been reported. However, studies on their impact response to newlineservice ammunition at ordnance velocities of impact as well as using newlinethermoplastic resins have been minimal. Experimental studies along with newlineextensive characterization and imaging are essential for providing information newlineconcerning the effect of variations of the materials and impact conditions that newlinecould predict their impact response. At present, a proper understanding of the newlinevariation of resins system and the thickness of composite laminates on the energy newlineabsorption mechanisms and ultimately the ballistic efficacy of relatively thick newlinearamid laminates is still quite limited. newlineIn this thesis, a systematic experimental study has been performed on aramid newlinefabric based composite laminates subjected to ballistic impact of hard core armor newlinepiercing (AP) projectiles under varying velocities. The aramid fabric Twaron® T- newline750, a product of Tejin Twaron® was used along with two types of resin matrix, newlinenamely; i) chemically modified epoxy (subsequently referred as epoxy) and II) newlinepolypropylene (PP). Laminates of varying thickness (10,15,20 and 25 mm) were newlineprepared using an optimized process procedure. These laminates were then newlinesubjected to ballistic impact of 7.62mm AP at