Micro-structural analysis of three dimensional braided composites with profiled section

The fundamental theory of braiding process of three dimensional braided preform with profiled section was described. The movement rules of the carriers in the machine plane and the planar and spatial yarns paths were analyzed systematically based on the preform with square section. The unit models in the joint rectangle region of interior, surface, and corner of three dimensional braided composites with profiled section were established besides the unit model of interior, surface, and corner of three dimensional rectangular braided composites by means of a control volume method. The surface of these models is parallel to the surface of perform, which is suitable for the analysis of the mechanical properties. In addition, the math relationship between braiding parameters was deduced on the hypothesis of the yarns with the elliptical cross-section. It would be a solid base for the analysis of the properties of three dimensional braided composites with profiled section.