中文摘要：

根据细观结构内界面的强约束特性，通过纤维一基体内界面切应力确定了共晶陶瓷棒体的细观应力场．然后分析了两相界面处位错塞积产生的应力集中，获得基体内的最大应力，当最大拉应力等于基体理论断裂强度时，得到共晶棒体的断裂强度的解析表达式．考虑共晶陶瓷棒体长度和方位的随机性，根据概率理论得到共晶陶瓷基复合材料的宏观强度的理论模型．结果表明复合材料的宏观强度与亚微米纤维的直径和长度、以及亚微米纤维、基体、共晶陶瓷棒体的弹性常数有关．理论与实验结果十分接近，说明文中理论模型是合理的，同时证明了共晶界面对陶瓷复合材料的重要影响．

英文摘要：

According to the strong constraining feature of interfaces of microstrctures, the micromechanical stress field in an eutectic ceramics rod was determined through the shear stress along fiber-matrix interfaces. Stress concentration due to dislocation pileup on fiber-matrix interfaces was analyzed, and the maximal stress in matrix was obtained. Letting the maximal stress in matrix equal to the theoretical strength, the fracture strength of the eutectic ceramics rod was gotten at once. Finally, taking into account the random orientation and length of eutectic ceramics rod,the macromechanical strength model of eutectic ceramics composites was built. The results show that the fracture strength was associated with the volume fraction,diameter and length of micron-fibers, and elastic constants of fiber, matrix and composite. The comparison between theoretical and tested results confirmed the rationality of the analytical model developed in this paper and also showed the important role of eutectic interfaces.