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《中国航空学报》2021,34(7):271-278
Morphing leading edge has great potential for noise abatement and aerodynamic efficiency improvement. The drooping effect is realized by bending of the flexible skin which encloses to form the leading edge. Since the flexible skin is often made of composite laminates of Glass Fiber Reinforced Plastics (GFRP), the lay-up sequences have become the determinant, which affects not only the morphing quality but also the manufacturing complexity. Two optimizing methods of lay-up sequences are comparatively studied. In the first method, the laminal quantities in 0°, ±45° and 90° vary independently, while in the second one, the concept of isotropic laminate unit [0/45/−45/90]s is employed and the unit quantity is the unique variable. Final evaluation demonstrates that for both methods there is insignificant impact to the overall morphing quality; however, specific concern is equally necessary for these two methods to the tip of the leading edge where the skin is at its minimum thickness and bears the most severe bending deformation. In terms of computational efficiency and post-processing labor, the second method has better performance. 相似文献
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利用热固性树脂基体在玻璃态转变温度(Tg)前后表现不同的材料特性,制备了Kevlar29芳纶织物/E51环氧树脂基复合材料和三根充气展开支撑管。给出了芳纶织物增强环氧树脂支撑管制备工艺,其中基体温度采用电阻丝加热控制,管体固化形状采用聚酰亚胺薄膜内胆充气加压方法控制。研究了支撑的折叠和展开特性,当T>Tg时卷曲折叠并冷却定型用于储存,然后采用二次加热T>Tg和充气加压方法控制展开,最终支撑管形状回复率100%。采用模态分析讨论了温度、树脂含量、织物铺层厚度和充气内压等参数对悬臂状态下支撑管的固有频率影响规律。结果表明:随充气压力增加、树脂含量提高、织物铺层厚度增加、基体温度降低,芳纶织物增强环氧树脂支撑管的固有频率增大。采用曲线拟合方法获得固有频率随充气压力和温度的变化规律,结果可为充气展开支撑管设计提供参考。 相似文献
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