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

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.