Ballistic performance and protection mechanism of aramid fabric modified with polyethylene and graphene

Aramid fabric has been widely used as a bulletproof material due to its lightness and comfort. However, multiple fabric layers must be used in one body armour, inevitably reducing its flexibility. To improve the ballistic performance of single-layer aramid fabric, we innovatively modify the fabric with polyethylene (LDPE) and graphene/polyethylene (GR/LDPE). Based on mechanical property tests, ballistic impact test and finite element analysis (FEA), the ballistic behaviours and key mechanism of modified fabrics are revealed. Experimental results show that LDPE or GR/LDPE modification does not change the tensile strength and Young's modulus much, but it greatly improves the interyarn friction of fabric. This improvement in the interyarn friction leads to twice ballistic limit velocities of pure aramid fabric; the ballistic limit velocities of pure, LDPE and GR/LDPE aramid fabrics are 105 m/s, 223 m/s and 216 m/s, respectively. However, excessive friction causes negative effects, which is why GR/LDPE/aramid fabric is weaker than LDPE/aramid fabric. The FEA results show that fabric motion and deformation are the main ways to resist impact as they absorb over 85% of the dissipated kinetic energy of the projectile. The novel modification method could be applied to the manufacturing of lightweight and effective body armour.