In-plane shear investigation of 3D surface-core braided composites

In-plane shear properties of three-dimensional (3D) surface-core braided composite are investigated by numerical simulation and experimental tests. Based on RVE models, the mechanical responses under in-plane shear load and the basic shear properties related to braiding parameters are predicted by using finite element method. Numerical results indicate that two groups of surface-cores possess distinct sensitivities to shear loads and identify the main load bearing components. In-plane shear tests are conducted to compare the effects of surface cuttings on the mechanical properties of present material and 3D 4-directional braided composite. The experimental data reveal that the cuttings degrade the shear moduli and strengths of the two materials to varying degrees. 3D surface-core braided composite can effectively restrain the decline of shear properties caused by cuttings. Scanning electron microscopy (SEM) is used to identify the distinct damage mechanisms of tested materials. (C) 2016 Elsevier Ltd. All rights reserved.