Abstract

This paper reports the effects of temperature and fiber architecture on the shear properties and failure mechanism of 3D MWK composites under compressive loading at room and elevated temperatures. The shear experiments of composites with three fiber architectures were performed at five different temperatures. Macro-fracture and SEM micrographs were examined to understand the deformation and shear failure mechanism. The results show that shear stress-strain curves show non-linearity and plastic fracture feature, and exhibit plastic platform at elevated temperatures. The temperature has significant effects on the shear properties which decrease significantly with increasing the temperature due to degradation of matrix properties, especially after 75 ^oC. The shear properties can be affected greatly by the fiber architecture and these increase significantly with the increase of 45 ^o direction fiber at different temperatures. The results also show that the damage and failure patterns of composites vary with the fiber architecture and temperature. At room temperature, the interfacial adhesion between fibers and matrix is high, the local delaminating and shear failure feature are prominent. At elevated temperatures, the composites become more softened, cracked and attain plasticity. The damage of matrix plastic and cracking, interface debonding, and fiber layer delaminating change significantly.

中文翻译：

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3D MWK玻璃/环氧复合材料在压缩载荷下的剪切性能与破坏机理的实验研究。

摘要

This paper reports the effects of temperature and fiber architecture on the shear properties and failure mechanism of 3D MWK composites under compressive loading at room and elevated temperatures. The shear experiments of composites with three fiber architectures were performed at five different temperatures. Macro-fracture and SEM micrographs were examined to understand the deformation and shear failure mechanism. The results show that shear stress-strain curves show non-linearity and plastic fracture feature, and exhibit plastic platform at elevated temperatures. The temperature has significant effects on the shear properties which decrease significantly with increasing the temperature due to degradation of matrix properties, especially after 75 ^oC.剪切性能会受到纤维结构的极大影响，并且在不同温度下，随着45 ^o方向纤维的增加，剪切性能会显着增加。结果还表明，复合材料的破坏和破坏方式随纤维结构和温度而变化。在室温下，纤维与基体之间的界面粘附力很高，局部分层和剪切破坏特征很突出。在升高的温度下，复合材料变得更加软化，破裂并获得可塑性。基体塑料的破坏和开裂，界面剥离和纤维层分层明显改变。