缝合复合材料的制备及层间断裂韧性研究

Research on preparation and delamination toughness property of stitched composite

采用锥管针刺技术将铺层平纹碳布在厚度方向上进行缝合,通过控制针距和行距,得到缝合密度不同的缝合预制体,利用树脂传递模塑成形工艺(RTM)制备出碳纤维/环氧树脂缝合复合材料。通过端部开口弯曲试验(ENF)方法,研究缝合复合材料的Ⅱ型层间断裂韧性及缝合密度对缝合复合材料Ⅱ型层间断裂韧性的影响。结果表明:缝合技术可有效地提高复合材料Ⅱ层间断裂韧性,缝合密度越大,层间增韧效果越显著,缝合密度为2.5mm×2.5mm时,GⅡC增量最大达到212%。同时,对试样的断口形貌进行了讨论,发现缝合线改变了复合材料的破坏模式。

Using taper tube acupuncture technology stitched the layer carbon cloth in the thickness direction.By controlling the stitch distance and line spacing,the stitched performs with different stitching densities were obtained,and carbon fiber/epoxy stitched composite was prepared by the resin transfer molding process(RTM).The effect of ModeⅡ interlaminar fracture toughness and stitch density on the fracture toughness of stitched composite was investigated by the end opening bending test(ENF).The research shown that the stitching technique can effectively improve the Mode Ⅱ interlaminar fracture toughness of composite.The greater the stitching density,the more significant the toughening effect between layers.With the stitching density was 2.5 mm×2.5 mm,GⅡC incremental maximum was up to 212%.At the same time,the fracture morphology of the sample was discussed and it was found that the stitch changed the failure mode of the composite.