Studies of fiber volume fraction and geometry of variable cross-section tubular 3D five-direction braided fabric

摘要

The requirements for the size and performance of fabric 3D five-directional braided variable cross-sectional tube can be met by using the appropriate reducing-yarn technique. Compared with the fabric processed with invariable cross-sectional yarns, the theoretical model of geometric structure and properties of variable cross-sectional yarn fabric is more complex. Based on the constituting method of yarn and the variation law of fabric, fiber volume fraction has changed greatly. The fabric is divided into different zones according to the constituting method of yarn in its unit cell, and the unit geometry models corresponding to different zones are established. The fabric geometry size and fiber volume fraction distribution are predicted. Research result shows that the model can describe the characteristics of braided fabric accurately. Therefore, the model lays theoretical foundation for the fabric structure design of the variable cross-sectional tubular fabric braided in 3D five-directions.