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将三维编织复合材料的纤维束和微裂纹分别看作圆柱型和圆币型夹杂，考虑了微裂纹的任意取向和增强纤维束的空间取向，采用等效夹杂法对含微裂纹的三维多向编织复合材料的热膨胀系数进行了细观力学分析，提出了预报含微裂纹三维多向编织复合材料热膨胀系数的方法，由于直接考虑了微裂纹的任意取向和增强纤维的空间取向，这种方法既可应用于一般含微裂纹的三维编织复合材料，也可应用于单向纤维增强复合材料．结合实例分别预报了单向纤维增强复合材料和四向编织复合材料的热膨胀系数与实验结果吻合较好．
The fiber bundles and microcracks of the three-dimensional braided composites are respectively considered as cylinder-type and coin-type inclusions. Taking into account the arbitrary orientation of the microcracks and the spatial orientation of the fiber bundles, the three-dimensional multidirectional The thermal expansion coefficient of braided composites was analyzed by meso-mechanics. The method of predicting the thermal expansion coefficient of micro-cracked three-dimensional multidirectional braided composites was proposed. This method not only considers the random orientation of micro-cracks and enhances the orientation of fibers, It can be applied to three-dimensional braided composite materials generally containing micro-cracks and can also be applied to unidirectional fiber-reinforced composite materials. The thermal expansion coefficients of the unidirectional fiber-reinforced composite and the four-directional braided composite are predicted respectively in good agreement with the experimental results.