Ballistic performance of B₄C/STF/Twaron composite fabric

This work proposes a new type of bullet-proof composite fabric, which is made of B₄C modified shear thickening fluid (STF) and Twaron aramid fabric. We conducted yarn pull-out test, ballistic impact test and finite element analysis (FEA) to investigate the ballistic performance of this new type of composite fabric. Based on the yarn pull-out test, it is found that the inter-yarn friction is greatly increased after the aramid fabric is impregnated with the B₄C modified STF. The ballistic test shows that the ballistic limit velocity of single-layer neat Twaron fabric can be improved from 114 m/s to 160 m/s by using pure STF while 179 m/s by using the B₄C modified STF where 10% B₄C of particle size W3.5 was added into the STF. For multiple layers of fabrics, the ballistic performance of 3-layer B₄C/STF/Twaron composite fabric is better than 3-layer neat Twaron whereas worse than 4-layer neat Twaron (which is of similar areal density to 3-layer composite). In order to study the ballistic properties of the composite fabric composed of fabric impregnated with B₄C modified STF and neat fabric, the ballistic performance of 6-layer fabric was studied. By optimizing the combination of fabrics, we found putting 1 layer of B₄C/STF/Twaron composite fabric in front of 5 layers of neat Twaron fabrics can maximize the overall ballistic resistance of the structure with the similar areal density. The simulation results agree well with the experimental results, which shows the path stress wave propagates and further emphasizes that the friction coefficient between yarns has a significant impact on the anti-impact property of fabric.