高性能纤维2.5D编织预制体是先进复合材料的结构增强相。高性能纤维的可织性反映了高性能纤维在织造成形加工过程中的抗损伤能力,其优劣直接影响织造效率和最终复材制品的性能和质量。合理设计高性能纤维2.5D编织预制体的密度是纤维可织性的前提。以2.5D浅交弯联结构为例,建立纤维束与其他接触部件的几何形态,根据纤维不同几何形态推出经纱密度与纬纱密度,进一步阐述了预制体的经纬向紧度、总紧度,对高性能纤维的编织难度进行评估,进而优化2.5D编织预制体的密度。

High-performance fiber 2.5D braided preforms is a reinforced structural phase of advanced composite materials.The weavability of high-performance fiber reflects the damage resistance of high-performance fiber in the weaving process,which directly affects the weaving efficiency and the performance and quality of the final composite product.A reasonable density design for high-performance fiber 2.5D braided preforms is a prerequisite for fiber weavability.The 2.5D shallow-interlock bending-linked structure was taken as an example to establish the geometric configuration of fiber bundles and other contact components.The warp density and weft density were deduced according to the different geometric configurations of the fibers.The warp and weft tightness and total tightness of the preforms were further expounded,and the weaving difficulty of high-performance fibers was evaluated,thereby optimizing the density of the 2.5D braided preforms.