High‐Strength, High‐Stiffness, High‐Toughness, and High‐Energy‐Absorption of 2D Carbon/Silk Plain‐Woven Hybrid Composites With 3D Structure Reinforcement

ABSTRACT Lay‐up sequence and reinforcement fabric architecture play significant roles in damage formation and crack progression in hybrid composites. Here a novel hybrid composite comprising a hierarchical sandwich structure of 2D carbon fiber fabric and 3D angle‐interlock silk fabric is successfully prepared. The sandwich hybrid hierarchical structures exhibit high strength, stiffness, toughness, and energy absorption characteristics because of the strengthening effect and anti‐delamination properties of the 3D silk layer‐to‐layer angle‐interlock and through‐the‐thickness angle‐interlock woven fabrics. The 3D silk through‐the‐thickness angle‐interlock reinforcement achieves superior structural integrity and stiffness compared to that of 3D silk layer‐to‐layer angle‐interlock reinforcement. The 2D carbon/silk plain‐woven hybrid composites with 3D silk through‐the‐thickness angle‐interlock reinforcement exhibit minimum delamination volume and vertical crack distribution because of the delamination cracks deflection and strain concentration offered by the through‐thickness z‐binder yarns. Micro‐computed tomography images of the sandwich hybrid hierarchical structures show high structural integrity and fracture concentration compared to those of traditional hybrid laminates containing 2D silk woven fabric reinforcements. This study provides a promising approach for the structural optimization design of high‐strength, high‐stiffness, high‐toughness, and high‐energy‐absorption of hybrid composites.