High velocity impact energy absorption characteristics of shear thickening fluid impregnated kevlar fabric

Abstract

High performance fabrics development has contributed to the development of body armor technology and improved ballistic performance all the while maintain flexibility. Shear Thickening Fluids (STF) allows further enhancement of ballistic resistance without hindering flexibility through an impregnation process to fabric. Investigations of the effect of STF impregnation on the ballistic performance of fabrics have been lim-ited to the impact velocity range below 700 m/s. Considering the hypervelocity impacts experienced by space structures in Low Earth Orbit (LEO) and the bumper configuration commonly employed by shielding of the structures where the impact velocity is considerably decreased through impact with bumpers, investigation of the energy absorption characteristics of neat Kevlar and STF impregnated Kevlar fabric specimens was con-ducted in this study. 100 nm diameter silica nanoparticles were dispersed in a solution of polyethylene glycol (PEG) and diluted with methanol for effective impregnation to the Kevlar fabric. High velocity impact exper-iments with projectile velocities between 1 and 2 km/s were conducted using a 2-stage light gas gun. The ex-periments revealed that the STF impregnation provides significant energy absorption enhancement in terms of equal volume, fabrication material cost, and areal density. Numerical simulations of the experimental cases were also conducted which resulted in deviation relatively in agreement to the energy absorption and post impact specimen formation results obtained empirically.