Experimental and Numerical Study on the Impact of Thread Density on Ballistic Performance of Multi‐Layer Aramid Plain Fabric for Body Armor

ABSTRACT This study evaluates the couple effects of thread density and layer number on the bullet resistance of single and multi‐layer plain fabrics, with the aim of improving the design of body armor for improved protection, comfort, and lightweight. Experimental ballistic test and finite element analysis were conducted, where three different thread densities (8, 9, and 11 ends/cm) of plain aramid fiber‐based fabrics were tested in 1‐layer and 12‐layer configurations. For the one‐layer fabric panel, the fabric with 9 ends/cm shows the best specific energy absorption. When the fabric layer is increased to 12, the three fabrics' specific energy absorption is almost on the same level because the fabric with lower thread density would absorb more KE and SE energy. The mechanism is that the fabric of 8 ends/cm exhibits a larger distribution of stress, and the last layer takes the stress faster than greater densities such as 9 and 11 ends/cm. The effect in low‐density fabrics presents a new concept, which opens up a promising avenue for developing improved performance and comfortable protective solutions while maintaining a balance between protection and flexibility.