Experimental analysis on the yarns section of three-dimensional five-directional braided composites

A series of cross-section images of three-dimensional (3D) five-directional braided composites were captured by the charge-coupled device (CCD) microscope, and then the yarns arrangements and their section patterns were discussed. The experimental results show that the yarns arrangements are different in the different cross-sections of 3D five-directional braided composites, and they are changing periodically. The braiding yarns section looks like a flat convex lens approximately. The axial yarns are almost straightened, but their sections are changing from fanlike shape to triangle shape alternately along their axes. The surface yarns arrangements are related to the interior yarns pattern, and their sections are near to the elliptical shape.