Experimental and Numerical Investigation of Tensile Mechanical Properties and Failure Mechanisms of <scp>3D</scp> Angle‐Interlock Woven Composites at Elevated Temperatures

ABSTRACT Three‐dimensional angle‐interlock woven composites (3DAWC) have extensive applications in aerospace, marine engineering, rail transportation, and related fields. During service, 3DAWC are inevitably subjected to high‐temperature environment. This study integrated experimental and numerical approaches to analyze the quasi‐static tensile mechanical properties of 3DAWC across a temperature range of 25°C–170°C and along both warp and weft directions. To this end, a finite element model was developed to simulate its thermo‐mechanical response. The results demonstrate that the stress–strain curves of 3DAWC exhibit linear elasticity at 25°C. With increasing temperature, both tensile strength and modulus exhibit progressive degradation. When temperature exceeds 110°C, the degradation exhibits accelerated progression, accompanied by pronounced nonlinear characteristics and plastic plateau formation in the curves. At room temperature, macroscopic damage manifests brittle fiber fracture and matrix interfacial debonding, with crack propagation primarily aligned with fiber orientation. The failure mechanism transitions to yarn splitting, delamination, yarn fracture, and matrix cracking at elevated temperatures, due to thermally‐activated interface degradation and enhanced resin plasticity.