Effect of fabric structural stability on the tensile property of bidirectional angle-interlock woven composites

Three-dimensional bidirectional angle-interlock woven (3DBAW) composites exhibit the orthogonal high modulus, which has the potential to be used in load-bearing components. 3DBAW preforms prepared using the certain and uncertain cross-sectional yarns exhibit various structural characteristics, and the mechanical properties of composites show the high variation. To investigate the effect of fabric structural stability on the elastic properties of 3DBAW composites and broaden its application, contrast analysis of quasi-static tensile properties of composite specimens was proposed, and the failure mechanism was analysed. The results showed that the high tensile initial elastic modulus of 3DBAW composites was attributed to the low curvature of load-bearing yarns. For composites with stable fabrics, the tensile process was smooth and steady owing to the uniform fiber spacing, and the tensile elastic modulus and strength show the smaller coefficient of variation. The tensile crack surfaces of composites with stable structural fabrics were regular, and making the full use of the load-bearing yarns. 3DBAW preforms with stable structure can effectively reduce the fluctuation of changes at the initial stage of loading, and the translaminar fracture and adhesive matrix failure are the main failure modes without the obvious interlaminar fracture. The results provided the support for the application of 3DBAW composite in load-bearing components.