An experimental study of bending properties of composites reinforced with triaxial and quadaxial warp-knitted glass fabrics was carried out in the 0°, 45°, and 90° directions at −30°C, 0°C, 20°C, and 40°C, respectively. The relationships between the stress–strain curves, bending strength, bending modulus, and temperature were obtained. The failure mechanisms at different temperatures were also analyzed based on the fracture morphologies and scanning electron microscope (SEM) images. The results indicated that the bending properties decrease slightly with the increase in temperature from −30°C to 20°C and decrease dramatically from 20°C to 40°C. The ultimate bending strength of triaxial and quadaxial warp-knitted composites decreases approximately 31.34% and 34.29%, respectively. In particular, the relationships between bending strength and temperature were also obtained by nonlinear fitting with the experimental data, which could be used to predict the bending behavior at different temperatures.

中文翻译：

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温度对多轴经编复合材料弯曲性能影响的实验研究

在-30°C、0°C、20°C和40°进行了0°、45°和90°方向的三轴和四轴经编玻璃织物增强复合材料的弯曲性能实验研究C、分别。获得了应力-应变曲线、弯曲强度、弯曲模量和温度之间的关系。还基于断口形貌和扫描电子显微镜（SEM）图像分析了不同温度下的失效机制。结果表明，弯曲性能随着温度从-30°C 到 20°C 的升高而略有下降，而从 20°C 到 40°C 则急剧下降。三轴和四轴经编复合材料的极限弯曲强度分别下降约31.34%和34.29%。特别是，