Abstract:

In order to investigate bending properties of carbon fiber composites with varied three-dimensional (3-D) woven structures, Shallow-Straight-Joint, Shallow-Bend-Joint and three-directional (3-D) Orthogonal as basic structures of composite performs were selected. All these performs were woven with carbon fibers and prepared to be composite samples by vacuum assistant resin infusion (VARI) technology. The bending properties in three directions of XYZ were tested and compared among the three structures. With comparing the bending performances of different structural composites, some conclusions are conducted as follows: 3-D orthogonal structural reinforcement preform has the highest contribution to the composite mechanical properties, because its warp yearns are straightly maintained in the structure. Composites with the Shallow-Straight-Joint structure has the highest cumulative bending strength in Z-warp direction and Z-weft direction. Its bending properties are relatively balanced in all directions. Owing to the frequently interlocking and the farthest warp crimp, composites with Shallow-Bend-Joint structure achieve the worst bending properties in the warp and weft direction.

Key words: carbon fiber, three-dimensional woven composite, bending performance, thick-section, angle-inerlock, three-directional orthogonal structure