Numerical Characterization of the Effects of Transverse Yarn Interaction on Textile Ballistic Response

Textile construction is well known for having a significant effect on the ballistic response of fabrics. One possible mechanism for this effect is the change in yarn-yarn interaction with changes in weave geometry. During an impact event, strain waves propagate through both fill and warp yarns. Energy transfer from warp to fill yarns and fill to warp yarns is a phenomenon that has been largely neglected in the field of ballistic modeling. Efforts to date have assumed that yarns are rigidly coupled and have the same stiffness characteristics in the throughthickness direction as they do in the axial direction. A newly developed computer program simulates transverse yarn interaction using an empirically derived model of crossed yarn stiffness. This program also models the complex, out-of-plane geometry of yarns woven into a fabric. These new features allow detailed analysis of fabric behavior including decrimping, a phenomenon that occurs when woven yarns straighten. Results to date indicate that the initial amount of crimping, decrimping, and yarn-yarn interaction has a significant effect on ballistic response models.