HYPODERMIC NEEDLE PUNCTURE OF SHEAR THICKENING FLUID (STF)-TREATED FABRICS

摘要

Shear thickening fluids (STF) are flowable at low shear rates but become macroscopically rigid at high shear rates. Previous studies have shown that STF-treated fabrics exhibit high penetration resistance under spike, stab, and low velocity ballistic threats. In this study, the resistance of STF-fabrics to needle puncture is explored. Factors controlling fabric resistance to needle puncture include needle diameter, fabric type, and the presence of the STF treatment. Multi-layer fabric specimens were placed on a foam backing and slowly loaded by hypodermic needles oriented normal to the specimen face. Load versus displacement was recorded, with fabrics of higher puncture resistance exhibiting higher peak loads before breakthrough. A range of needle sizes, needle types, fabric types, and treatments were tested. The loading data shows behavior characteristic of previous theoretical predictions for fabric puncture. The results illustrate important interactions between needle size, fabric architecture, and treatments, with STF application providing important improvements in puncture resistance under many conditions.