Experimental determination of ballistic performance of newly developed multiaxis non-interlaced/non-Z E-glass/polyester and 3D woven carbon/epoxy composites with soft backing aramid fabric structures

The aim of this study is to understand the energy absorption mechanism and identified failure modes of the developed multiaxis non-interlaced/non-Z E-glass/polyester and 3D woven carbon/epoxy composite plates with soft backing para-aramid fabric structures. Two structures, multiaxis non-interlaced/non-Z E-glass/polyester composite plate and soft back layered para-aramid fabric, and 3D woven carbon/epoxy composite plate and multiaxis non-interlaced/non-Z E-glass/polyester composite plate with soft back layered para-aramid fabric, absorbed considerable impact energy when a high speed projectile’s metal jacketed section was stopped. The damage zones of both structures were investigated after impact. 3D woven carbon/epoxy plate showed a small damaged area compared to that of the non-interlaced/non-Z E-glass/polyester plate. This was because the Z-fiber suppressed the impact load, but the local area was severely damaged in the form of fiber and matrix breakages. There was no intra and inter fiber damage around the impacted area in the 3D carbon/epoxy composite plate, whereas there was intra and inter fiber damage around the impacted area in the non-interlaced/non-Z E-glass/polyester plate. It was thought that the impact load in the E-glass/polyester structure was redistributed around the local impacted area. Fiber damage in the soft back layered fabric extended from the decomposition of the fiber ends, partial and total fiber breakages to yarn pull-out and crimp recovery. Fiber decomposition results in friction between the fabric and the projectile which generates thermal load in the soft structure.