Influence of fabric structure on the tensile and flexural properties of three-dimensional angle-interlock woven composites

The application of three-dimensional angle-interlock woven composites (3DAC) as structure components in aerospace field creates tremendous demands for mechanical properties. A new kind of 3DAC with bidirectional fabric structure was proposed in this paper. The tensile properties of 3DAC and 3D bidirectional angle-interlock composites (3DBAC) were conducted by quasi-static tensile tests. According to three-point bending method, the flexural properties of 3DAC and 3DBAC were experimentally tested. The load-displacement curves of specimens showed that 3DBAC presented the better stability due to the higher noncrimp rate. The stress-strain curves indicated that the tensile modulus of elasticity in 3DBAC was larger than 3DAC, and the flexural modulus of 3DBAC gained an advantage over 3DAC. Based on the mesostructure of fabrics, the failure characterizations of specimens were analyzed. Results showed that the yarns in 3DBAC bear the maximum load, and the tensile fracture was regular. Through the analysis of crack morphologies, it is found that 3DBAC exhibits better flexural properties. The results supply the theoretical support for the manufacturing of structural components in the field of lightweight design.