立体织物增强复合材料热传导性能研究

发布时间：2018-05-18 22:37

本文选题：立体织物 + 减纱方法　；参考：《天津工业大学》2017年硕士论文

【摘要】：本课题研究立体织物增强复合材料的热传导性能,立体织物外形和结构具有可设计性,制备工艺简单,利用石英纤维织造立体织物增强复合材料的具有耐高温、耐侵蚀、抗热冲击和透微波等特点,可满足在一定外界环境下保护天线罩的作用。立体织物作为增强材料领域的后起之秀,其编织参数和结构对材料热传导性能的影响研究有待进一步细化。本课题以石英纤维和环氧树脂为原料,采用热常数分析仪TPS2500S,通过实验方法分析比较纤维体积分数、内部编织角等工艺参数以及不同减纱方法和织物结构对立体织物增强复合材料热传导性能的影响,得到了一些有意义的研究结论。这些结论为立体织物增强复合材料在热传导方面的设计应用和理论研究提供必要的依据,其主要结论如下:三维编织复合材料的导热系数与纤维体积分数正相关,随着纤维体积分数从45%增大到60%,三维五向编织复合材料的轴向导热系数从13.9%提高到21.9%,其径向导热系数从15.6%提高到23.5%;在纤维体积分数为50%的情况下,当编织角从20°提高到30°,复合材料的径向导热系数提高了20%,而其轴向导热系数减小了 18%,三维编织复合材料热传导性能沿着轴向和径向呈现出各向异性,编织角越小各向异性越明显;减纱能降低三维编织复合材料的热传导性能,其中集中减列的影响最明显,轴向和径向分别降低了 3.2%和3%,减细度的影响效果不是很显著,轴向和径向分别降低了 1.5%和1.0%。在相同纤维体积分数情况下,三维编织复合材料的热传导性能低于层合及2.5D复合材料的热传导性能。其中3D5d编织复合材料的轴向热传导性能比3D4d和3D6d好,其径向热传导性能则低于3D4d和3D6d编织复合材料;2.5D复合材料的热传导性能在轴向及径向均高于层合复合材料。采用编织纱为六边形,轴纱为八边形的单胞模型来模拟3D5d编织复合材料的纱线交织情况,探索采用LBM方法和"半格划分方案"来预测3D5d复合材料导热系数。通过本文的研究,为该类材料的工艺选择、性能设计、结构优化等奠定了基础,推动三维编织复合材料在航空航天领域的进一步应用。
[Abstract]:In this paper, the thermal conductivity of three-dimensional fabric reinforced composites is studied. The shape and structure of three-dimensional fabric are designable, the preparation process is simple, and the three-dimensional fabric reinforced composite made of quartz fiber has high temperature resistance and corrosion resistance. The characteristics of thermal shock resistance and microwave permeation can satisfy the protection of radome in certain external environment. As a rising star in the field of reinforcements, the effects of braiding parameters and structures on the thermal conductivity of the materials need to be further refined. In this paper, quartz fiber and epoxy resin were used as raw materials, and TPS 2500S was used to analyze and compare the volume fraction of fiber by experimental method. The effects of weaving angle, yarn reducing methods and fabric structure on the thermal conductivity of three-dimensional fabric reinforced composites have been studied in this paper. These conclusions provide a necessary basis for the design, application and theoretical study of three-dimensional fabric reinforced composites. The main conclusions are as follows: the thermal conductivity of three-dimensional braided composites is positively correlated with the fiber volume fraction. With the increase of fiber volume fraction from 45% to 60%, the axial thermal conductivity of three-dimensional five-direction braided composites increases from 13.9% to 21.9%, and the radial thermal conductivity increases from 15.6% to 23.5%, and when the fiber volume fraction is 50%, When the braiding angle is increased from 20 掳to 30 掳, the radial thermal conductivity of the composites increases by 20 and the axial thermal conductivity decreases by 18. The thermal conductivity of the three dimensional braided composites exhibits anisotropy along the axial and radial directions. The smaller the braiding angle is, the more obvious the anisotropy is, the smaller the yarn is, the lower the thermal conductivity of 3D braided composite is, and the more obvious the effect of concentrated reduction is, the axial and radial decreases are 3.2% and 3% respectively, the effect of fineness reduction is not obvious. Axial and radial decreases of 1.5% and 1.0%, respectively. Under the same fiber volume fraction, the thermal conductivity of 3D braided composites is lower than that of laminated composites and 2.5D composites. The axial heat conduction property of 3D5d braided composite is better than that of 3D4d and 3D6d, while the radial heat conduction property of 3D4d and 3D6d braided composite is lower than that of 3D4d and 3D6d braided composite. The axial and radial thermal conductivity of 3D5d braided composite is higher than that of laminated composite. A unit cell model with hexagonal and octagonal yarns was used to simulate the interleaving of 3D5d braided composites. The LBM method and the semilattice scheme were used to predict the thermal conductivity of 3D5d composites. The research in this paper lays a foundation for the process selection, performance design and structure optimization of this kind of materials, and promotes the further application of 3D braided composites in the field of aerospace.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332

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