不同结构厚截面三维机织碳纤维复合材料的弯曲性能对比

Bending properties comparison of thick-section carbon fiber composites based on different three-dimensional woven structures

为准确分析不同结构厚截面复合材料不同方向上的弯曲性能差异,通过设计织造三向正交、浅交直联、浅交弯联3种典型机织结构的厚截面碳纤维三维机织物,并采用真空辅助树脂成型工艺制备了近似纤维体积含量的碳纤维复合材料板,对其进行了XYZ方向的弯曲实验。结果表明:三向正交结构由于内部纤维束近似平直,碳纤维束自身性能得到最大利用,对应复合材料经向弯曲强度最好;浅交直联结构复合材料的Z经和Z纬弯曲强度累加值最大,其厚度截面上的综合弯曲性能最好,且其他各方向的弯曲强度较为均衡;浅交弯联结构内部纱线交织摩擦损伤严重,且经纱屈曲程度最大,对应复合材料经纬向弯曲性能均为最差。

In order to investigate bending properties of carbon fiber composites with varied threedimensional（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 assised 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 Zwarp 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.