This work investigated the static and fatigue properties of 3D stitched composite and 2D laminated composite subjected to three-point bending loads. Four stress levels were carried out to investigate fatigue characteristics of the composites. The failure propagation of the composites and their fracture morphology were captured in detail using the high-speed camera. The results demonstrated that the static flexural strength of 3D stitched composite was lower than 2D laminated composite but the modulus of 3D stitched composite was higher than that of the latter. Besides, the fatigue failure mechanism of 3D stitching composite was dependent on the stress levels. Though the fatigue life of the 3D stitching composite was not as good as 2D laminated composite, the failure of stitching thread proved to be able to judge the catastrophic damage of the 3D stitching composite, which is important for indicating the safe use of the composite structure.

这项工作研究了 3D 缝合复合材料和 2D 层压复合材料在三点弯曲载荷下的静态和疲劳性能。进行了四个应力水平以研究复合材料的疲劳特性。使用高速相机详细记录了复合材料的失效扩展及其断裂形态。结果表明，3D缝合复合材料的静态弯曲强度低于2D层压复合材料，但3D缝合复合材料的模量高于后者。此外，3D 缝合复合材料的疲劳失效机制取决于应力水平。虽然3D拼接复合材料的疲劳寿命不如2D层压复合材料，