中文摘要：

根据三维正交机织复合材料的结构特点,在假设纤维束横截面为矩形的基础上建立一种单胞模型,该模型由3组互相正交的纤维与基体组成。首先利用这一模型,推导出纤维体积分数与纤维粗度、机织密度等织物参数的关系式,通过测量单胞单元的单层厚度得到纤维体积分数,计算值和实验值较为吻合。然后在假定纤维和基体均为线弹性材料的基础上,利用材料力学方法推导出了3个正交方向的杨氏模量表达式,该表达式简单明了,给出了三维正交机织复合材料杨氏模量与纤维和基体的杨氏模量以及纤维体积分数间的关系,算例的计算结果与实验值有良好的一致性,这说明所建立的单胞模型具有合理性。

英文摘要：

Considering the structure characteristics of 3D orthogonal woven composite（3D OWC）, a cell model composed of three orthogonal bundles of fibers and matrix was proposed based on the assumption that the fiber bundle has the rectangular cross section. According to the cell model, an equation relating the fiber volume fraction and the woven parameters （such as the fiber roughness, weaving density and so on） was obtained. The relatively simple formulas of Young＇s modulus of 3D-OWC were developed by the assumption that both the fiber and matrix are elastic. With the new formulas, three dimensional orthogonal composite＇s Young＇s modulus can be got by the fiber modulus, matrix modulus and fiber volume fraction. The fiber volume fraction and elastic modulus calculated by the equations are in good agreement with the experiments. It is concluded that the proposed cell model is effective and valuable, and it will be useful in the study of 3D-OWC mechanical properties.