Analyzing stiffness variations in 3D woven composites: A multi-instrumental study on Glass/Kevlar hybridization effects under tensile and shear loads

This study focuses on exploring the influence of glass/Kevlar hybridization on the tensile and shear properties of 3D woven composites. The study delves into the behavior of two distinct hybridization scales, inter-ply and intra-tow hybridizations at the outer layers of the 3D woven composites, and compares them with a full-Kevlar configuration while maintaining consistent fabric architecture across all three configurations. The hybridization process for Kevlar 3D woven composites is conducted in the weft direction. Tensile properties are systematically examined along both the warp and weft directions to comprehensively assess the effect of hybridization. To gain a thorough understanding of stiffness changes during loading, all tensile tests are monitored using digital image correlation and acoustic emission analysis techniques. Furthermore, the study investigates the influence of various hybridization techniques on the shear properties and behavior of 3D woven composites. The analysis of shear stiffness variation in all composite configurations is conducted through the utilization of full-field strain distribution obtained from digital image correlation. The tensile test results indicate that hybridization with glass positively influences stiffness recovery along the hybridization direction, whereas the baseline configuration performs better in the perpendicular to the hybridization direction. On the other hand, the shear test results reveal that, although the baseline configuration exhibits a lower shear modulus compared to its hybrid counterparts, it experiences less loss in shear stiffness.