Numerical simulation and empirical comparison of the high velocity impact of STF impregnated Kevlar fabric using friction effects

The application of shear thickening fluids (STF) allows further enhancement of ballistic resistance without hindering flexibility by impregnation. Considering the muzzle velocity of modern rifles with high performance cartridges, investigation of the high velocity impact energy absorption characteristics of neat and STF impregnated Kevlar fabric was conducted numerically in this study. Numerical study of the impact energy absorption characteristics utilizing the commercial tool LS-DYNA was conducted with a focus on minimal computational cost and friction which was assumed to be the dominant energy absorption mechanism of STF impregnated fabric during impact. The simulation results were compared with high velocity impact experiment results conducted previously with projectile velocities between 1 and 2. km/s using a 2-stage light gas gun. The major factor behind the energy absorption mechanism was assumed to be the friction between the impact projectile, fabric, and yarns within the fabric during impact where experimentally obtained static and dynamic friction coefficients yielded analysis results in good agreement visually with experimental results, however, contrasting trends in energy absorption in relation to the impact velocity suggest that the assumption made in this study is insufficient in fully expressing the effect of high velocity impact on neat and STF impregnated fabric.