双轴向经编织物T700/BMI6421复合材料力学性能
Mechanical properties of bi-axial warp-knitted fabric T700/BMI6421 composites
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摘要: 对双轴向经编织物T700/双马来酰亚胺树脂(BMI)6421复合材料进行了弯曲性能和层间剪切性能测试, 以同状态无经编线的单向布T700/BMI6421复合材料作对比, 分析了经编织物T700/BMI6421复合材料的力学特性, 采用微观金相、SEM分析了经编线引起的纤维层内部结构变化。结果表明, 引入经编线导致纤维束面内排列产生扰动, 降低了复合材料的弯曲性能, 45°方向上弯曲模量下降约26%; 经编线的绑缚使纤维层结合更加紧密, 提高了层间剪切性能, 0°方向上层间剪切强度提高约13%。证实了复合材料液体成型工艺中, 经编织物可替代单向布等传统预成型体。Abstract: Comparing with the unidirectional(UD) cloth T700/bismaleimide(BMI)6421 composite, mechanical properties of warp-knitted fabric T700/BMI6421 composite were studied. Bending properties and interlaminar shear properties of warp-knitted fabric T700/BMI6421 composite were tested. The variety in fabric structure caused by warp-knitted thread were demonstrated with metallographic microscope and SEM images. It is shown fiber distortions caused by warp-knitted thread decrease the bending performance. The bending modulus is 26% lower than the unidirectional cloth reinforced composite in the 45°direction. The interlaminar shear performance is improved by stitching structure which make the fiber layer tighter. The interlaminar shear strength(ILSS) is about 13% higher than the unidirectional cloth reinforced composite in the 0°direction. It is confirmed that traditional unidirectional cloth could be replaced by warp-knitted fabric in liquid composite molding process.