Effects of Temperature and Fiber Orientation on the Tensile and Joining Behavior of Short Carbon Fiber Reinforced PA6T Composites

ABSTRACT Short carbon fiber reinforced polyamide 6 T (SCF/PA6T) composites possess superior mechanical performance and molding efficiency, showing great application potential in aerospace load‐bearing components. This work explored the temperature and fiber orientation effects on tensile behavior, and the interactive effects of fiber orientation and edge distance on the failure modes of bolted joints. The results indicate obvious temperature sensitivity and anisotropy in tensile performance. Matrix softening at elevated temperatures markedly degrades tensile strength and elastic modulus, while 0° specimens retain superior mechanical properties through axial fiber loading. Interfacial debonding dominates the fracture of 0° specimens, whereas 90° specimens fail mainly through matrix rupture. For single‐lap bolted joints, edge distance and fiber orientation jointly determine failure modes. Increasing edge distance weakens the anisotropic difference in joint performance, and the transverse fiber arrangement in 90° specimens effectively suppresses crack initiation and propagation near the hole edge, whereas 0° specimens are susceptible to hole‐edge cracking under constrained edge distances. This study reveals the multi‐factor coupling mechanism of mechanical and joining behavior, and provides experimental support for the structural joint design and engineering application of SCF/PA6T composites.