纤维增强弹性体基复合材料单纤维拔出试验细观力学分析

MICROMECHANICAL ANALYSIS OF SINGLE-FIBER PULL-OUT TEST OF FIBER-REINFORCED ELASTOMER MATRIX COMPOSITES

建立了含纤维、基体以及粘弹性界面层三相纤维增强弹性体基复合材料单纤维拔出试验细观力学分析模型,得到了单纤维拔出过程中纤维轴向应力、界面层轴向剪应力、基体轴向应力和轴向剪应力的计算公式。以芳纶纤维增强弹性体基复合材料为对象,研究了纤维埋入长度、纤维体积含量以及界面层厚度对单纤维拔出过程中纤维和界面层应力分布的影响。并将所建模型与部分文献所提模型相比较。结果表明:随着x/l(沿纤维埋入长度方向的坐标)的增加,纤维轴向应力单调增加,而界面层轴向剪应力基本先减小后变大;不同的纤维埋入长度、纤维体积含量以及界面层厚度,纤维轴向应力和界面层轴向剪应力会表现出不同的分布规律。

A micromechanical model for single-fiber pull-out test of fiber-reinforced elastomer matrix composites is established. It includes fiber, matrix and viscoelastic interface. The formulas to calculate the axial stress of fiber, the shear stress of interface, and the axial and shear stress of matrix are obtained. Moreover, for Kevlar aramid fiber reinforced elastomer matrix composites, this paper studies the influences of the coated fiber length, the fiber volume fraction and the interface thickness on the stress distributions of fiber and interface. Some analysis results show that, with the increase of the embedded fiber length, the axial stress of fiber increases monotonically, but the shear stress of interface decreases following an increase at the beginning. The stress distributions of fiber and interface change with the variation of the coated fiber length, the fiber volume fraction and the interface thickness.