Multidirectional Stitched Layered Aramid Woven Fabric Structures and their Experimental Characterization of Ballistic Performance

The aim of the research was to develop light and enhanced energy absorbed layered ballistic structures. For this reason, various ballistic structures were developed. These structures form two groups: multiaxially stitched and unstitched. Each group further consists of four structure types: (i) 14-layer Kevlar 29 woven fabric; (ii) 14-layer Kevlar 129 woven fabric; (iii) 7-layer Kevlar 29 fabric and 7-layer Kevlar 129 fabric; and (iv) 12-layer Kevlar 29 fabric oriented with respect to basic fabric direction at an angle of +/- 45 degrees and 2-layer Kevlar 129 fabric. The Kevlar 29 and 129 fibers were considered to have 2.9 and 3.4 GPa tensile strengths and 70 and 99 GPa tensile modulus values, respectively, and the properties of the fibers were equalized in fabric form, but the Kevlar 129 fiber had a lower unit weight fabric (g/m(2)). Each of the developed structures were affected by five types of threat: 0.22, 0.38 round nose, 9 mm full metal jacketed, 0.357 jacketed soft point and 7.62 full metal jacketed projectiles. The results show that there were no significant energy absorption differences between multiaxis stitched and unstitched structures. However, conical depths upon impact on the multiaxis stitched structures were small compared to those of the unstitched structures. This result might be useful, especially in the design of soft vest applications.