Study on flexural stress of T beam of 3-D multidirectional braided composites

To optimize the microstructure design of the load bearing assembly of 3-D multidirectional braided composites,the flexure properties of three dimensional multidirectional braided composites T beam were simulated and analyzed.Based on the fine structure unit cell model,the elastic constants of 3-D,4-,5-,and 6 directional braided composites with different braiding angles were calculated by stiffness volume average method.The stress and strain of 3-D multidirectional braided composites T beam were computed by utilizing FEM Patran/Nastran software.The effects of fiber interlaced topology and microstructure parameters on the bending resistance of the composites were discussed.The results show that when the fiber volume content is fixed,the elasticit of 3-D six-directional braided composites is more close to isotropic when compared with 3-D 4-or 5-directional ones.Also,bigger braiding angle improves the bearing ability of the T beam.This method can be used as a reference for the microstructure design of 3-D shaped braided composites.