Investigating the quasi-static puncture resistance of p-aramid nanocomposite impregnated with the shear thickening fluid

Abstract

The effect of impregnating p-aramid fabrics with shear thickening fluids on their quasi-static puncture resistance performance has been investigated. To prepare the shear thickening fluid, 12 and 60-nm silica particles have been dispersed in polyethylene glycol by means of mechanical mixing. The results of rheological tests indicate that the reduction of particle size leads to the increase of suspension viscosity, increase of critical shear rate, and the diminishing of the frequency of transition to elastic state for the shear thickening fluids. Samples of p-aramid impregnated fabrics were subjected to the quasi-static puncture resistance test according to the American Society for Testing and Materials standard D6264. The quasi-static puncture resistance increased 4.5 times for samples with 35 wt% silica concentration relative to the neat sample. In particular, with the reduction of particle size, the samples undergo less deformation and can withstand larger loads at each shear thickening fluid concentration. However, at low and medium concentrations (15 and 25 wt%), the reduction in the particle size has a large effect on the load-bearing capacity of the fabrics. But in the case of 35 wt% concentration for both the 12- and 60-nm particles, the difference between maximum loads withstood by the fabric is negligible.

Body armor for stab and spike protection, Part 1: Scientific literature review

“…Baharvandi et al. 151 investigated p -aramid nanocomposites impregnated with the STF in quasi-static puncture test. Silica particles of 12 and 60 nm were dispersed in polyethylene glycol to prepare the STF for application to the p -aramid fabric.…”

Effects of silica morphology on the shear‐thickening behavior of shear thickening fluids and stabbing resistance of fabric composites

“…Yarn pull‐out and fabric windowing were two typical stabbing resistance mechanisms in neat fabrics, in which the yarns could spread apart and the penetrator passed between yarns without significant fiber fracture . However, for STF‐treated samples, the addition of STF into the fabric generally restricted the motion of yarns and fibers and preserved the rearrangement of yarns and fibers, which prevents the sharp tip of the knife from pushing aside yarns and filaments and penetrating between them. Therefore, the STF‐treated aramid targets supported much higher loads and greater displacements before pierced than the neat target in quasi‐static impact tests, which may be one reason for the enhancement in stabbing resistance of fabrics.…”

Effect of silica weight fraction on rheological and quasi-static puncture characteristics of shear thickening fluid-treated Twaron® composite

“…The experimental observations indicate that the neat samples experience larger local deformations than the treated samples where the load is applied [27,28]. The influence of molecular weight of polymer medium [9,15,29] and silica nanoparticle size [10,12,30,31] on rheological and mechanical properties of the fabric-STF composite have already been discussed. The performance enhancement provided by the STF is suspected to be due to the increased frictional interaction between the yarns [3,12,[29][30][31][32][33].…”

“…The influence of molecular weight of polymer medium [9,15,29] and silica nanoparticle size [10,12,30,31] on rheological and mechanical properties of the fabric-STF composite have already been discussed. The performance enhancement provided by the STF is suspected to be due to the increased frictional interaction between the yarns [3,12,[29][30][31][32][33]. The increased friction resulting from the presence of nanoparticles between the filaments and the shear thickening phenomena as well as the friction between the filaments and the penetrator lead to the higher occurrence of fiber breakage than the sliding of fibers under high-velocity impact loading [4,12,20,34].…”