Enhanced Mechanical Properties of T‐Stiffened Panel Composites via an Innovative 3D Woven Carbon Fiber Preform

ABSTRACT This study introduces a novel integrated three‐dimensional (3D) woven T‐shaped carbon fiber preform. This preform aims to improve the mechanical properties and structural integrity of T‐stiffened panel carbon fiber composites. In this preform, the stiffener and skin are fully integrated through the angle‐interlocking structure. This design significantly optimizes the triangular zone and distinguishes it from traditional preforms made by lamination or folded weaving. All three preform types were fabricated into resin matrix composites using the identical vacuum‐assisted resin transfer molding process. Mechanical testing and fracture morphology analysis revealed that the failure mode in the triangular zone of the integrally‐woven 3D carbon fiber composite T‐stiffened panel (IW‐TSP) was primarily dominated by fiber fracture, effectively avoiding interlaminar cracking. The IW‐TSP achieved a flexural strength of 186.23 MPa, representing approximate increases of 14.9% and 51.7% over the laminated 3D carbon fiber composite T‐stiffened panel (L‐TSP) and folded‐woven 3D carbon fiber composite T‐stiffened panel (FW‐TSP) samples, respectively. Furthermore, its maximum tensile fracture load reached 12545.2 N, significantly exceeding that of the L‐TSP (9610.2 N) and FW‐TSP (6318.9 N). Results indicate that this integrated 3D weaving technology enhances fiber continuity and optimizes the load path in the triangular zone. It provides a superior alternative for mitigating the weak interfacial issues in T‐stiffened structures, demonstrating promising potential for aerospace applications.