Bending behaviors of carbon fiber-aluminum honeycomb sandwich structures, that are toughened by stitched fiber belts, are experimentally and numerically studied. It is found that the stitched fiber belts show potential to enhance the peak load of sandwich specimens by up to 44.3%, and to arrest interfacial crack growth. Firstly, FE models are proposed for the sandwich structures with stitched carbon fiber belts, and the FE models are verified by three-point bending tests. Secondly, the effects of stitched carbon fiber belts on bending behaviors of sandwich beam are studied. Combining the experimental and numerical results, the main toughening mechanism of stitched fiber belts is observed. The stitched fiber belts increase bonding area between face-sheets and honeycomb core, on one hand, and therefore enhance the interfacial strength. On the other hand, the angled fiber belts inside the core are found to enhance load bearing capacity and transverse shear stiffness.

中文翻译：

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缝合纤维带碳纤维-铝蜂窝夹层结构的弯曲行为及增韧机理

对缝合纤维带增韧的碳纤维-铝蜂窝夹层结构的弯曲行为进行了实验和数值研究。研究发现，缝合纤维带具有将夹层试样的峰值载荷提高高达 44.3% 并阻止界面裂纹扩展的潜力。首先，提出了缝合碳纤维带夹层结构的有限元模型，并通过三点弯曲试验对有限元模型进行了验证。其次，研究了缝合碳纤维带对夹芯梁弯曲行为的影响。结合实验和数值结果，观察了缝合纤维带的主要增韧机理。一方面，缝合纤维带增加了面板和蜂窝芯之间的粘合面积，从而增强了界面强度。另一方面，发现芯内的成角度的纤维带可以增强承载能力和横向剪切刚度。