Parametric study of energy absorption mechanism in Twaron fabric impregnated with a shear thickening fluid

• Rheological test showed highest shear thickening of the fluid with 45 wt% particles.
• Friction at fiber–fiber level played major role in STF impregnated fabric.
• Higher rate of loading induced higher frictional force for STF impregnated fabric.
• Drop impact test on STF saturated foam indicated good energy absorption.

This study quantitatively investigates the significance of different forms of friction phenomena in a Twaron fabric impregnated with a shear thickening fluid (STF). The study then examines the energy absorption and high velocity impact performance of such fabric. Silica oxide Aerosil OX50 in 35, 40 and 45 wt% were used as a suspending material dispread in polyethylene glycol. Poly-aramid Twaron fabric and open cell flexible foam were used as the reinforcing material for friction and energy absorbing assessments. Pull out, quasi-static penetration and slid friction tests were conducted to assess the frictional force at fiber–fiber level, also tensile, drop impact and high velocity impact tests were conducted on Twaron fabric and flexible foam impregnated with the STF. Both SEM and TEM images confirmed good dispersion of silica particles in the suspension. Rheological results revealed shear thickening occurring for all three compositions with 45 wt% composition showing the highest shear thickening at lower shear rate. STF impregnated Twaron fabric showed a significant frictional force effect at fiber–fiber level in all three friction assessment tests conducted. This enhancement in frictional effect attained higher values for some of the tests conducted at higher rate of loading. Both impact tests revealed promising results.