层-层正交角联锁机织物及其复合材料的结构及其层切破坏机制研究

采用无损高分辨率X射线成像(显微X-CT)技术对层-层正交角联锁机织物以及复合材料内部结构进行分析，并研究了层间剪切强度与结构之间的关系；通过三维重构展现了机织物的层-层正交角联锁的微观结构，观察到机织物内部的单丝扭转、挤压现象；依据机织复合材料中孔隙和高密度杂质在三维空间的分布，计算了其相应的占比。结果表明：层间剪切实验后的机织复合材料虽然宏观形貌保持了良好的完整性，但内部存在孔隙变形、分层、纤维弯曲、片层断裂等现象；层-层正交角联锁机织结构有效提高了复合材料的层间力学性能，内部的缺陷对复合材料的力学性能有较大的影响；无损高分辨X射线成像技术是研究纤维增强复合材料内部复杂结构特性的有利手段。

Structural and laminar damage mechanisms in layer-to-layer orthogonal angle-interlock woven fabrics and composites

In order to analyze the internal structure and the load bearing of layer-to-layer orthogonal angle-interlock woven fabrics and composites, X-ray computed tomography (Micro CT) volume pixels was used to extract non-destructively the internal structure. The micro-structure of layer-to-layer orthogonal angle-interlock the woven fabric was observed by three-dimensional reconstruction, and the twisting and extrusion of monofilaments inside the fabric was observed. The distribution of pores and high-density impurities in the composite were reconstructed and the quantitative estimations were carried out. The results show that the composite demonstrated good integrity after the laminar damage test, there are phenomena shch as pore deformation, delarmination, fiber bending and lamella fractures inside. It was confirmed that the unique structure of the layer-to-layer orthogonal angle-interlock woven fabric effectively improved the interlaminar mechanical properties of the composites, highlighting the importance of non-destructive X-ray computed tomography in analyzing the imaging data of fiber reinforced composites.