【摘要】 为了防止复合材料T型加筋壁板在服役过程中因剪切和弯矩作用而发生筋条与蒙皮的脱粘失效,引入了缝合技术来提高筋条-蒙皮界面的结合性能。采用自主研发的单线弯针缝合设备来缝合干纤维,通过真空辅助树脂灌注技术(VARI)固化成型,脱模后制成缝合T型加筋壁板试样。通过对试样进行剪切和弯曲试验,研究缝合的增强机理以及缝线细度对T型接头性能的影响规律。结果表明:在剪切应力作用下,缝合试样的峰值载荷比未缝合试样有明显提高,随着缝线细度增大,T型接头的峰值载荷升高,缝线细度增大到1 500 D时,峰值载荷提高55.0%。在弯曲应力作用下,随着缝线细度的增大,T型接头的峰值载荷先升高后降低。缝合对T型接头在两种不同应力下的初始损伤载荷均无明显影响。更多还原

【Abstract】 In order to prevent the debonding failure between stiffener and skin due to shearing and bending loads during service of T-stiffened composite panel, stitching technology was introduced to improve the interface performance between stiffener flange and skin. The self-developed sti-tching machine was used to stitch dry fibers, then stitched preform was cured and formed by vacuum assisted resin infusion(VARI) technology, and stitched T-stiffened panel samples were prepared after demoulding. The reinforcement mechanism of stitching and effects of thread fineness on properties of T-joints were researched through shear and bend tests. Results show that, under shearing stress, the ultimate failure load of stitched samples is significantly higher than that of unstitched samples. With the increase of thread fineness, ultimate failure load of T-joints increases. When thread fineness increases to 1 500 D, the ultimate failure load increases by 55.0%. Under bending stress, as thread fineness increases, ultimate failure load increases first and then decreases. Stitching has no obvious effect on the initial failure load of T-joints under two different stresses.更多还原