Energy Absorption of Ballistic Impact in Hybrid Kevlar/Polypropylene Woven Fabric Composites Preloaded Under Simple Shear Mode: Response Surface Methodology Modeling Utilizing a Box–Behnken Design

ABSTRACT Enhancing the protective performance of body armor requires optimizing fabric architecture and processing parameters to improve resistance against high‐speed impacts. This study investigates the ballistic energy absorption behavior of hybrid thermoplastic composites fabricated from prestressed Kevlar/polypropylene woven fabrics subjected to controlled simple shear model deformation. Woven fabrics were produced with three weft densities (3, 4, and 5 cm ⁻¹ ) and a constant warp density of 4 cm ⁻¹ . Based on simple shear model, a novel shear testing device was developed to apply simultaneous opposing shear deformation in two parallel fabric layers. This setup was integrated into a hot press system for composite fabrication under controlled composite processing conditions. Composite panels were tested against high‐velocity projectiles using a gas gun. The effects of fabric architecture (weft density and shear locking angle) and composite processing parameters (temperature, time, and pressure) on ballistic energy absorption were studied. Response Surface Methodology (RSM) using the Box–Behnken design revealed that optimal energy absorption occurred at 300 kg/cm ² , 20 min, 170°C, and at the maximum shear locking angle ( β _max ).