Energy analysis of fabric impregnated by shear thickening fluid in yarn pullout test

摘要

Impregnating fabrics with shear thickening fluid (STF) to form bi-phase composite is a potential method to improve the bulletproof resistance of flexible fabrics. In this study, a planetary ball milling method was used to prepare STF with 62, 65 and 70 wt% mass fraction using silica (SiO2) as dispersing phase and ethylene glycol as dispersant. The Kevlar 49 plain woven fabric was impregnated to form bi-phase composite. The yarn pull-out tests of neat fabrics and STF impregnated fabrics with loading speeds of 100, 500 and 1000 mm/min were carried out respectively. The experimental results show that STF impregnated fabrics have higher yarn pull-out loads than neat fabrics, and show a correlation of yarn pullout speed. A new energy absorption model is proposed to analyze the energy absorption mechanism in yarn pullout test. It is concluded that the work done by external force in yarn pull-out test can be equivalent to the energy dissipation of friction between yarns. The friction energy dissipation of STF impregnated fabrics is obviously increased compared with that of neat fabrics.