Ballistic impact characterization of $SiO_2$ colloidal suspension impregnated fabrics and application to armor systems

Abstract

Fabric armor made of high tenacity fabrics has been widely used for flexible personnel body armor although it provides limited protection under high-energy impact loading. Recently, the impregnation of shear thickening fluid (STF) into high strength fabrics has drawn attention since it enhances the ballistic performance without the loss of flexibility of the fabric. However, the essential impact mechanism that enhances the energy absorption induced by shear thickening fluid is not clearly understood yet. In this study, the high tenacity fabrics impregnated with STF comprising of the spherical $SiO_2$ particles is investigated to identify the impact energy absorption mechanism induced by the shear thickening within fabrics. In order to examine the dynamic response of $SiO_2$ colloidal suspension (SCS) impregnated fabric subjected to ballistic impact loading, extensive experimental investigation through ballistic impact tests, low speed impact tests, and yarn pull-out tests as well as rheology tests have been carried out. Also, computational analysis of woven fabric incorporated with the effect of SCS impregnation has been performed to complement experimental observation. The proposed computational model to account for the effect of SCS impregnation has been shown to reasonably represent the physical features of the SCS impregnated fabrics subjected to ballistic impact. It contributes to a better understanding of how SCS impregnation plays a role in energy absorption within fabrics. It has been shown through experimental and computational studies that SCS impregnation affected the interfacial friction of filaments and yarns, which contributes to larger transfer of the impact energy to interaction of individual yarns in the fabric, resulting in improvement of ballistic performance over neat fabrics of equivalent areal densities. The effects of various parameters associated with the SCS impregnation on the ballistic performance have been identified as well as speci...