High-Velocity Impact Behavior of Aramid/S2-Glass Interply Hybrid Laminates

This work investigates the effect of hybridization and stacking sequence on the ballistic impact response of S2-glass/aramid/epoxy laminates. Different laminates were manufactured by vacuum infusion, one with only aramid fabrics (12 layers, K12), two with only S2-glass fabrics (12 or 18 layers, Gl12 and Gl18) and five interply hybrids (Gl3K9, [GlK]6, K6Gl6, Gl6K6, Gl9K3). Ballistic tests were performed according to EN1522- FB3, with the.357 Magnum FMJ projectile. The ballistic curves were determined to obtain the ballistic limit velocity (VBL), and in-plane damage area and through-the-thickness damage were analyzed. For the impact at 430 m/s, all laminates were perforated, and the Gl18 exhibited greater specific absorbed energy (26.6 J.m2/kg), with lower thickness and in-plane damage than the K12 (22.6 J.m2/kg) with a similar areal density (≈0.77 g/cm2). No significant differences in ballistic limits (pairing effect) were observed for the [GlK]6, Gl6K6 and K6Gl6 hybrids, and the Gl3K9 hybrid exhibited a positive hybrid effect. The areal density of laminates has shown a great influence on the final ballistic response. The results have shown that hybridization of aramid composites with S2-glass may enhance the impact absorption capability of hard composite armors, however, the ballistic limit velocity, which is a crucial parameter to assess ballistic shield performance, reduced.