Reinforcement effect of shear thickening fluid on impact properties of aramid, basalt, and carbon fiber reinforced polymer using a split Hopkinson pressure bar

This study focuses on investigating the impact properties of fiber-reinforced polymer (FRP) materials impregnated with shear thickening fluid (STF) under high strain rates using a split Hopkinson pressure bar (SHPB) test. The study involves the preparation of three types of FRP materials, namely aramid FRP (AFRP), basalt FRP (BFRP), and carbon FRP (CFRP), which are subsequently impregnated with STF to develop FRP composite materials (referred to as FRP-STF). The STF used in the experiment is synthesized by dispersing 15.0 wt.% and 20.0 wt.% of 12 nm silica in Polyethylene glycol. The results of rheological tests show a significant shear thickening effect on viscosity for both STFs. Furthermore, the SHPB tests demonstrate a noteworthy improvement in the impact performance of AFRP, BFRP, and CFRP under high strain rates when impregnated with STF. However, the extent of this improvement varies among the different types of FRP materials. For instance, BFRP exhibits the highest increase in stress peak, reaching 58.9% under a strain rate of 3800 s(-1) and an STF mass fraction of 20%. AFRP demonstrates the most significant increase in energy absorption, reaching 226.8%. When subjected to a strain rate of 6100 s(-1), the AFRP-20% STF composite exhibits a highly favorable stress response, while the CFRP-20% STF composite shows an energy absorption of 710.5 J, approximately 3.3 times higher than that of pure CFRP. These trends are also evident in the energy absorption per unit density curve.