Abstract
Three-dimensional composites with more than 3 axes consist of roving or rod-shape unidirectional composite materials which are arranged to different orientations and resin matrix filled among them. This paper describes the arrangement of the fiber bundles in 3-dimensional composites with 3 to 7 axes, and proposes the calculating method to determine the size and the shape of the fiber bundles and the volume fraction of the fiber in the composites. Based on this method, the structures of representative 3-dimensional composites with 4 to 7 axes were clarified. Furthermore the shape of section and the volume fraction of the fiber bundles were found to change by not only the number of axis or its arrangement, but also the size of the unit element or the sectional area of the fiber bundles.
