Experimental and Statistical Analysis of the Effects of Shear Thickening Fluid Formulation Parameters on the Ballistic Performance of Aramid Fabrics

ABSTRACT Aramid fabrics impregnated with shear thickening fluids (STFs) have significant potential for enhancing flexible ballistic protection systems. This study experimentally and statistically investigated the effects of carrier fluid, SiO 2 particle size, and STF concentration on the ballistic performance of STF‐impregnated aramid fabrics. Eight STF formulations were prepared using polyethylene glycol (PEG 400) and dipropylene glycol (DPG) as carrier fluids, SiO 2 particle sizes of 15–35 nm and 300 nm, and STF concentrations of 55% and 65%. Ballistic tests were conducted using a single‐stage gas gun, and the energy absorption results were evaluated using a 2 3 full factorial experimental design and analysis of variance (ANOVA). All STF‐impregnated samples exhibited higher energy absorption than neat aramid fabric. The highest energy absorption, 257.16 J, was achieved by STF 1B/Aramid containing PEG 400, 15–35 nm SiO 2 , and 65% STF. ANOVA revealed that particle size had the greatest contribution to energy absorption (35.74%), followed by STF concentration (21.38%) and carrier fluid (17.19%). The carrier fluid–particle size interaction was also statistically significant ( p < 0.05). Overall, smaller SiO 2 particles (15–35 nm) provided superior ballistic energy absorption compared with 300 nm particles.