Excellent ballistic performance of B4C/shear thickening fluid (STF)/ZnO aramid composite fabric

Aramid fabrics (such as Twaron fabric) are widely used in flexible protective equipment due to their high strength and flexibility. Recent studies have shown that growing zinc oxide (ZnO) nanoparticles on fiber surface can enhance the ballistic performance of single-layer fabrics. However, the enhancement effect on multi-layer fabrics is not ideal. This work proposes a new method of modifying aramid fabrics with Boron Carbide/STF/ZnO (BSZ). The mechanical and friction properties of BSZ modified fabrics increased first and then decreased with the increase of shear thickening fluid (STF) solid content. The thickness of BSZ fabric only increased by 6.7% compared with neat fabric. Compared with neat fabric and ZnO modified fabric, the ballistic limit velocity ( v bl ) of single-layer BSZ fabric increased by 103.3% and 29.2%, respectively, and the areal density only increased by 7.1%. The v bl of three-layer BSZ fabric increased by 77.8% and 36.4% compared with neat and ZnO modified fabric, respectively. The enhanced protection of BSZ fabric can be attributed to friction gain, mechanical interlocking, stacking effect, and stress dispersion effect of nanoparticles. The discrepancy between numerical and experimental results was within 10%. The failure characteristics of the fabric in numerical simulation was highly consistent with the results in experiment, further indicating that BSZ modification improved the ballistic performance of the fabric by enhancing the inter-yarn friction, tensile properties, and particle diversity of the fabric.