Compression and bending properties of 3D braided tubular composites

3D braided tubular composites have a wide range of applications in load-bearing structural components. The mechanism of the influence of fiber properties on their deformation and failure evolution during load bearing is a pressing issue. In this paper, the failure behavior of two kinds of fiber-reinforced tubular composites, high-modulus high-strength and high-toughness, was investigated. Through axial compression and three-point bending tests, with the help of DIC technology, the mechanical properties of different fiber braided tubular composites were studied. It is found that the deformation distribution of the high-strength high-modulus tubular composites changes earlier, and the deformation is mainly concentrated in the region where shear slip occurs. The deformation distribution change of high-toughness tubular composite occurs later, deformation gradually concentrates in the middle of the “bulging” region; high-strength high-modulus tubular’s compression and bending strength are 56% and 50% higher than that of high-toughness tubular composites; It’s compression and bending energy absorption are 20.9% and 68% higher than that of high-toughness tubular composites, respectively. This indicates that the high strength and high modulus of fibers can make up for the weakness of their poor toughness resulting in less energy absorption. This study can provide theoretical guidance for the design of 3D braided tubular composites.