Response of glass fiber-reinforced hybrid shear thickening fluid (STF) under low-velocity impact

Abstract

This paper addresses the response of glass fiber-reinforced shear thickening fluid (STF) under low-velocity impact. Experimental tests were performed according to ASTM: D5628 for initial impact energy 6.89 J and for samples with STF+ nanoclay (30% silica and 3% clay nanoparticles), STF+ nanoclay (30% silica and 1% clay nanoparticles), STF (30% silica nanoparticles), and STF (20% silica nanoparticles).The effect of impregnating glass fabrics with STFs on their quasi-static puncture resistance performance has been investigated. A STF was prepared successfully, and rheological behavior was investigated. The results of rheological tests indicate that the increase in the fraction weight of nanosilica and nanoclay leads to the increase in suspension viscosity and reduction in the critical shear rate. One of the disadvantages of STF is high concentration. Glass fabrics were soaked in STF/ethanol solution to prepare STF–glass fabric composite and STF–nanoclay–glass composite. For better immersion of fibers, at first STF is diluted in ethanol, and then, the fibers are left therein for a specified period in order to impregnate all fibers with the fluid. After this stage, to eliminate the ethanol in the sample, it is heated at a temperature range of 60–70 °C. The composite's sensitivity to the impact will be reduced through ethanol combining with the fluid and its elimination. Quasi-static resistant tests were carried out on both the neat glass fabrics and STF–glass fabric and STF–nanoclay–glass fabrics composites using a hemispherical penetrator based on the areal density. This study clearly displays a significant enhancement in penetration resistance of glass fabric impregnated with different combination of STF and STF–nanoclay. In sample with higher weight fraction of nanosilica and nanoclay, displacement to yield point is higher and resistance to penetration does not have much difference.