Experiments and progressive damage analyses of three-dimensional full five-directional braided composites under three-point bending.

Experimental and numerical studies on the bending properties of three-dimensional full five-directional (3DF5D) braided composites are presented in this article. Three-point bending tests of the braided specimens with different braiding angles were first preformed. Then, the full-scale specimen model was constructed and a strength analysis method based on repeated unit-cell (RUC) model was established to describe the strength characteristics of the 3DF5D braided composites. The differences between yarn configurations in corner, surface and interior RUCs were considered and continuum damage models were introduced into the components such as yarns and matrix of the RUCs in the method. This linked the macroscopic nonlinear response with the damages in the microstructures. Good agreements were achieved in the load-deflection curves and damage morphology between experimental and numerical results. POLYM. COMPOS., 37:2478-2493, 2016. © 2015 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]