Based on the 3D 5-directional( 5d) and 6-directional( 6d) braided structure, four kinds of Kevlar/carbon hybrid 3D braided composites were prepared.Then,the influence of hybrid style or hybrid percentage on the longitudinal tensile properties and the flexural properties in both longitudinal and transverse directions of 3D5d and 3D6d braided composites were investigated. With the same hybrid style,the experimental studies show that both tension and flexural properties in longitudinal direction of 3D 5d brai-ded composites are higher than those of 3D 6d braided composites,but its flexural properties in transverse direction are lower than those of 3D 6d braided composites.With the same braided structure,the tensile and flexural properties in longitudinal direction of the hybrid composites using carbon fiber as axial yarn and transverse yarn are higher than others. When 3D 5d braided composites using carbon fiber as braided yarn,Kevlar fiber as axial yarn and 3D 6d braided composites using Kevlar fiber as braided yarn,carbon fi-ber as axial and transverse yarn,it is found that their flexural properties in transverse and the crack propagation resistant are im-proved obviously.Through the tailor of Kevlar/carbon hybrid style,the designability of Kevlar/carbon hybrid 3D multi-directional braided composites can be realized further.%基于三维五向和三维六向编织结构,设计并制备了4种芳纶/炭混编三维编织环氧复合材料,对比分析了芳纶/炭纤维混编方式(混编比)对三维五向和三维六向编织复合材料纵向拉伸性能、纵向和横向弯曲性能的影响. 结果发现,同一种混编方式下,芳纶/炭三维五向编织复合材料纵向拉伸和弯曲性能均高于三维六向编织复合材料,而其横向弯曲性能均低于三维六向编织复合材料;同一种编织结构下,炭纤维为轴纱/六向纱的芳纶/炭混编三维编织复合材料纵向拉伸和弯曲性能较高;炭纤维为编织纱、芳纶纤维为轴纱的三维五向编织复合材料和芳纶纤维为编织纱、炭纤维为轴纱/六向纱的三维六向编织复合材料的横向弯曲性能和抗裂纹扩展能力明显提高. 通过设计芳纶和炭纤维的混编方式,可进一步实现三维编织复合材料性能的可设计性.
展开▼
