中文摘要：

为了预测非屈曲织物增强复合材料的力学性能，建立了纤维束的正六边形单胞和非屈曲织物复合材料的长方形单胞，并重点推导了正六边单胞的方程边界条件。通过跨尺度逐级计算这两个单胞的有效弹性常数，得到了非屈曲碳纤维织物增强环氧树脂基复合材料的宏观有效弹性性能和强度。对该非屈曲织物复合材料在拉伸载荷下的累计失效进行了有限元损伤分析。结果表明：初始损伤发生在富树脂区或横向纤维束，损伤在富树脂区与横向纤维束内逐步扩展，最后向纵向纤维束扩展并迅速导致整体失效；非屈曲织物增强复合材料的面内拉伸模量的计算预测值非常接近实验值，面内拉伸强度计算值略小于实验值。

英文摘要：

To predict the mechanical behaviors of non-crimp fabric reinforced composites, hexagonal unit cell （UC） and rectangular UC were developed to represent the fiber tow and composite, respectively. The equation boundary condition of the fiber tow UC was derived in detail. The macro-scale effective stiffness and strength of a non-crimp carbon fabric reinforced epoxy composite was obtained by calculating the effective elastic constants of the two UCs at different length scales. Finite element damage analyses were performed to study the progressive failure of the composite in tension. Results show that the initial damage occurs in either the resin pockets or the transverse tows. Damage develops within the resin pockets and transverse tows, and progresses into the longitudinal tows and causes the composite failure very quickly. The predicted value of tensile modulus of the non-crimp fabric reinforced composite is very close to experimental value, and the calculated value of tensile strength is slightly less than that of experimental value.