三维编织复合材料圆管轴向压缩性能及破坏机理

Axial Compressive Properties and Failure Mechanism of 3D Braided Composite Tube

通过真空辅助树脂传递模塑成型技术,制备了三维多层缠绕编织、三维五向面芯编织和三维七向编织3种不同三维编织复合材料圆管。系统分析了三维编织复合材料圆管的纱线轨迹,分别开展了准静态轴向压缩试验,研究了不同编织工艺对三维编织复合材料圆管的压缩承载、破坏模式及吸能性能的影响。结果表明:不同编织结构圆管的轴向承载能力和破坏机制存在显著差异。三维多层缠绕编织圆管的环向纱体积含量较高,能有效承担轴向载荷,其轴向承载能力明显高于其余两类编织圆管。但由于纤维间载荷传递性能较弱,易发生脆性破坏,导致吸能效果最差。而三维五向面芯编织和三维七向编织圆管具有紧密交织的纱线结构,径向编织纱能有效限制剪切裂纹扩展,从而引发渐进稳定的开花式破坏,此类破坏具有较好的吸能特性。三维五向面芯编织圆管纤维断裂更加充分,吸能效果最为优异。

Three-dimensional(3D)braided composite tubes,including 3D multi-layer braided,3D fivedirectional surface-core braided,and 3D seven-directional braided tubes,were fabricated by vacuum assisted resin transfer molding.The yarn traces of the 3D braided composite tubes were systematically analyzed.The quasi‑static axial compression tests were carried out to investigate the effects of different braiding processes on the compression bearing capacity,failure mode and energy absorption performance of three‑dimensional braided composite tubes.The results showed that the axial bearing capacity and failure mechanism of circular tubes with different braided structures were significantly different.3D multi‑layer braided tubes maintained a high volume content of circumferential yarn,which can effectively bear the axial load,making its axial bearing capacity significantly higher than the other two types of braided circular tubes.However,due to the weak load transfer performance between fibers,brittle failure was easy to occur,resulting in the worst energy absorption effect.3D five‑directional surface‑core braided and 3D seven‑directional braided tubes had closely interwoven yarn structures,and the radial braided yarn can effectively limit the shear crack growth,thus leading to gradual and stable flowering failure.Such failure had better energy absorption characteristics.The fiber of the 3D five-directional surface-core braided tube broke more fully,and the energy absorption effect was the most excellent.