航空学报 > 2025, Vol. 46 Issue (7): 430878-430878   doi: 10.7527/S1000-6893.2024.30878

平纹碳/碳复合材料指尖密封径向刚度特性多尺度研究

宋丹龙1,2(), 王源昊1, 华珂伊1, 杜春华1, 张延超1, 荆云娟2   

  1. 1.西安理工大学 机械与精密仪器工程学院,西安 710048
    2.陕西元丰纺织技术研究有限公司,西安 710038
  • 收稿日期:2024-06-27 修回日期:2024-07-15 接受日期:2024-08-05 出版日期:2024-08-13 发布日期:2024-08-10
  • 通讯作者: 宋丹龙 E-mail:songdanlong@xaut.edu.cn
  • 基金资助:
    国家自然科学基金(51805429)

Multi-scale study of radial stiffness characteristics of plain C/C composite finger seals

Danlong SONG1,2(), Yuanhao WANG1, Keyi HUA1, Chunhua DU1, Yanchao ZHANG1, Yunjuan JING2   

  1. 1.School of Mechanical and Precision Instrument Engineering,Xi’an University of Technology,Xi’an 710048,China
    2.Shaanxi Yuanfeng Textile Technology Research Co. ,Ltd. ,Xi’an 710038,China
  • Received:2024-06-27 Revised:2024-07-15 Accepted:2024-08-05 Online:2024-08-13 Published:2024-08-10
  • Contact: Danlong SONG E-mail:songdanlong@xaut.edu.cn
  • Supported by:
    National Natural Science Foundation of China(51805429)

摘要:

碳纤维增强碳基体(C/C)复合材料具有自润滑、耐磨损等优良性能,与动密封技术需求和应用环境相匹配,可以显著提高指尖密封的服役寿命,但是各向异性的力学性能、非均质的微观结构和复杂的曲线构型导致C/C复合材料指尖梁的力学特性复杂多变,限制了指尖密封的封严效果和服役寿命的提高。因此,首先通过平纹编织C/C复合材料多尺度编织结构和性能分析,构建了C/C复合材料指尖密封片的多尺度有限元模型;然后,采用多尺度有限元法深入分析了铺层数量、径向位移以及不同位置的C/C复合材料指尖梁径向静刚度的变化规律和周向分布特性;最后,搭建了指尖梁径向刚度试验台,并对不同位置的C/C复合材料指尖梁径向静刚度进行了试验验证。研究结果显示:圆弧形指尖梁的载荷随径向位移的增大而线性增大,其径向刚度保持不变;3层碳纤维布的指尖梁径向刚度约是单层的3倍,周向分布指尖梁的径向刚度呈现先减小后增大的周期性分布规律,周期为90°,最小刚度约为最大刚度的68%,较大的径向刚度差异会导致局部磨损和迟滞泄漏问题,研究结果为C/C复合材料指尖密封结构优化与性能研究提供了参考和依据。

关键词: 指尖密封, C/C复合材料, 平纹编织, 多尺度建模, 刚度特性

Abstract:

Carbon fiber reinforced carbon matrix (C/C) composite have unique excellent characteristics such as self-lubrication and wear resistance, making them well-suited to the technical requirements of dynamic seals and their corresponding application environments. These characteristics can significantly improve the service life of finger seals. However, the anisotropy performance, heterogeneous micro-structure and the complex curve lead to the complex mechanical characteristics of C/C composite finger beams, which further affects the sealing performance and service life of finger seals. Therefore,a multi-scale finite element model of the C/C composite finger seals was firstly constructed by analyzing the multi-scale structures and performance of the plain woven C/C composite laminates. Secondly, the variation trend and circumferential distribution characteristics of radial static stiffness of C/C composite finger beams with different positions and number of layers were analyzed deeply by the multi-scale finite element method. Finally, a radial mechanical performance test platform of the finger beam was built, and radial static stiffness of C/C composite finger beams with different angular positions was verified by experiments. The research results show that the load of circular finger beam increased linearly with the radial displacement, and its radial stiffness kept constant. The radial stiffness of the finger beam with three layers of carbon fiber fabric was about 3 times that of the finger beam with single layer. The radial stiffness of circumferential distributed finger beams presents a periodic distribution characteristic of decreasing first and then increasing, with a period of 90°, and the minimum stiffness was about 68% of the maximum stiffness. A large difference in radial stiffness will lead to local wear and hysteretic leakage. The research provides a reference and basis for the structure optimization and sealing performance of C/C composite finger seals.

Key words: finger seal, C/C composite, plain weave, multi-scale modeling, stiffness characteristic

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