Investigation of the tensile properties and failure mechanism of integrally-braided 5D carbon/phenolic composites

Longitudinal (braiding direction) tensile tests were performed for integrally-braided 5D carbon/phenolic composites with different braiding angles and fiber volume fractions, and transverse tensile tests were also done for comparison. The main mechanical properties were obtained. After the test, fracture morphology and microstructure observation were performed to further understand the deformation and the failure mechanism. The experimental results show that the braiding angle still has a primary influence on the mechanical properties of 5D composites, and the processing quality of 5D composites has significant influence on their mechanical properties. In addition, it is found that the longitudinal tensile failure mechanism of the composites is very different from the transverse tensile failure mechanism.