EFFECTS OF FABRIC TARGET SIZE, SHAPE, AND CLAMPING ON THE V50 BALLISTIC IMPACT PERFORMANCE OF ARAMID SOFT BODY ARMOR

摘要

The V50 probabilistic impact performance of non-backed aramid fabrics used in soft body armorrnis studied using several clamping configurations including 4-sided, 2-sided, circular, diamond,rnand corner-clamped frames. For a constant fabric target size, the V_(50) velocity was found to bernsensitive to the exposed fabric shape and clamping configuration. The impact response was alsornsensitive to the precise projectile impact location which varied between impacts occurringrndirectly on a yarn and at the inter-yarn gap. Corner-plate clamped fabrics showed tearing at thernsharp corners while corner-point clamped fabrics showed distinct fabric deformation and failurernmechanisms over various projectile velocity regimes. In addition, the effects of fabric target sizernon the V50 velocity was studied by considering 4-sided, diamond, and circular clamped fabrics ofrnvarious exposed areas. A logarithmic function well described this relationship for all three shapesrnconsidered with the 4-sided clamped fabrics showing poorer relative V_(50) impact performancernthan the circular and diamond clamped fabrics as the target size increased. This studyrnimportantly demonstrates that it is not just the intrinsic system parameters such as the fabricrngeometry, material, and architecture that govern its ballistic impact performance, but alsornextrinsic parameters such as the impact testing methodology. This is an important considerationrnwhen assessing or comparing the ballistic impact performance of various fabric armors.