Enhancement in ballistic performance of composite hard armor through carbon nanotubes

Evaluating the effect of nano-particle additives in Kevlar® 29 impact resistant composites

“…The previous work had shown a change in the epoxy matrix's cracking and failure due to the enhancement via carbon nanotube additives [25]. This work expands the scope by looking at both MWCNT and CSR nano-particles at three different loading levels to look at how the combination of micron and nano-sized particles can improve ballistic performance by enabling distribution of the stress wave down to the energy absorption mechanisms of the nano-particles through the micron sized particles.…”

“…5c-e. Because the back face deformation and therefore the Kevlar Ò fiber elongation is similar for all three panels, the additional energy absorption leading to superior ballistic resistance performance is coming purely from the amount of energy absorbed during crack propagation through the resin matrix. Previous reported work had identified the addition of milled carbon fiber and carbon nano-tubes resulted in a tearing failure of the epoxy [25], rather than a brittle fracture. In this study Raman spectroscopy was conducted to understand the influence of both additive classes mixed with milled carbon fiber filler and the residual state of the fibers in an effort to shed light on the energy absorption mechanisms.…”

“…For clarity, CNT 2-1.5 represents a Kevlar Ò 29 composite with 2% milled fiber and 1.5% multi-walled carbon by weight. techniques followed closely with the previous work reported on the subject [25]. The samples were tested in an indoor range with the muzzle of the test barrel mounted 16.5 feet (5.02 m) away from the target panel and positioned to produce 0°obliquity impacts.…”

“…If this projectile is seen to be a partial penetration (i.e. did not pass fully through the panel into a witness panel placed behind the tested panel), the next projectile is shot at an increased velocity [24,25]. Post shot visual inspection was also conducted examining the degree of delamination of the composite as well as the entrance and exit zones.…”

Aramid–multiwalled carbon nanotube nanocomposites: effect of compatibilization through oligomer wrapping of the nanotubes

“…The aromatic polyamides commonly referred to as ‘aramids’, because of their high thermal stability, specific strength, chain stiffness and low density, have large‐scale commercial and industrial exploitation. Poly( m ‐phenylene isophthalamide) and poly( p ‐phenylene terephthalamide) marketed under the trade names of fibre Nomex® and Kevlar®, respectively, offer outstanding tensile strength coupled with excellent high‐temperature properties . Aromatic polyamides, e.g.…”