衬入纬编电热层碳/环氧复合材料层间断裂韧性实验研究

Experimental study on interlaminar fracture toughness of carbon/epoxy composites embedded with weft-knitted electrothermal layer

  • 摘要: 为飞行器曲面部件开发具有电热防冰/除冰功能的碳/环氧复合材料,选用镍铬合金(Cr20Ni80)丝,设计制备了纬平针、1×1罗纹和双罗纹三种结构的纬编电加热织物,将电加热织物作为碳纤维缎纹织物对称铺层复合材料的中间电热层,采用真空辅助树脂灌注工艺制备了含纬编电热层的碳/环氧复合材料。在0.3 W/cm2功率密度下通电180 s,三种电热复合材料试样均升温至70℃以上,且表面温度分布均匀。对三种电热复合材料进行了短梁剪切和I型层间断裂韧性测试,实验结果表明,相较于未含电热层的碳/环氧复合材料,含纬平针、1×1罗纹及双罗纹电热层的试样,其层间剪切强度保留率分别可达84.60%、79.34%和87.71%;起始断裂韧性(GICinit)保留率分别为74.36%、91.03%和96.15%;扩展断裂韧性(GICprop)保留率分别为97.22%、93.52%和88.89%。采用数字图像相关技术和轮廓仪观测分析了试样应变分布和破坏形貌,发现纬编电加热织物的线圈结构对复合材料的层间破坏行为具有一定的调控作用。

     

    Abstract: To develop carbon/epoxy composites with electrothermal anti-icing/de-icing capabilities for aircraft structural components, the nickel-chromium (Cr20Ni80) wires were weft-knitted into plain, 1×1 rib, and interlock electrothermal fabrics. Serving as the electrothermal layer, these were embedded into the midplane of carbon/epoxy laminates and prepared via vacuum-assisted resin infusion. Under a power density of 0.3 W/cm2 for 180 s, all composites exceeded 70℃, with a uniform surface temperature distribution. Short-beam shear and Mode I interlaminar fracture tests indicated that, compared to the pristine carbon/epoxy composites, for specimens with plain, 1×1 rib, and interlock electrothermal layers, the shear strength retention rates reached 84.60%, 79.34% and 87.70%; the initial fracture toughness (GICinit) retentions reached 74.36%, 91.03% and 96.15%, the propagation fracture toughness (GICprop) retentions reached 97.22%, 93.52% and 88.89%, respectively. Digital image correlation and profilometry were employed to observe and analyze the strain distribution and fracture morphology of the specimens, Research demonstrates that the loop structure of the weft-knitted electrothermal fabric plays a role in regulating the interlaminar failure behavior.

     

/

返回文章
返回