Investigation of the Low Velocity Impact Behaviour of Shear Thickening Fluid Impregnated Kevlar, Hybrid (Kevlar/Carbon) and Carbon Fabrics

In this study, unlike the previous studies focusing merely on high-performance fabrics (i.e, aramid based Twaron, Kevlar) low velocity impact behaviour of neat and shear thickening fluid (STF) impregnated kevlar, hybrid (Kevlar/Carbon) and carbon fabrics was investigated. In the first stage, STFs with the silica concentrations of 5 wt%, 10 wt%, 15 wt% and 20 wt% were produced separately and the rheological measurement of each individual fluid concentration were carried out. In the second stage of the study, kevlar, hybrid and carbon fabrics were impregnated by STF having a silica content of 20 wt%. Yarn pull-out tests, dynamic puncture tests and quasi-static (QS) puncture tests were carried out on both the neat and impregnated fabrics. The rheological measurements showed that, the resulting silica/PEG400 suspensions exhibit good shear thickening behaviours, however it is not the case for those under a critical silica concentration. The yarn pull out tests revealed that, STF enhances the inter-yarn frictions of all three types of fabric. Correspondingly, STF positively affected the dynamic puncture resistance of kevlar and hybrid fabrics, while it had an adverse effect on carbon fabric. Besides, STF caused increases on the QS puncture resistances of all three fabric types.