Influence of Yarn-Reduction Technique on Bending Properties of Tapered 3D Braided Composites

Abstract

The influence of distance between yarn-reduction cross-sections on bending properties of double-times yarn-reduction composites was investigated in this paper. Tapered 3D braided composites were prepared with the distances between two yarn-reduction cross-sections ranging from 1 pitch to 5 pitches. Bending properties in the center of the two yarn-reduction cross-sections were tested and the fracture morphologies were compared. Results show that damages mainly occur near the second yarn-reduction cross-section when the distances are 1 pitch to 3 pitches. However, obvious damages are found in the center of the two yarn-reduction cross-sections when the distances are 4 and 5 pitches. As the distances between yarn-reduction cross-sections increase from 1 pitch to 4 pitches, bending properties of the composites increase, too. For composites with 5 pitches distance, their bending properties are nearly the same as those of the composites with 4 pitches distance.