通过类比复合材料湿扩散与热传导的控制方程以及边界条件,以Halpin&Tsai模型为基础,发展了一个考虑了纤维/基体界面相的三相复合材料湿扩散模型,并研究了纤维界面随机损伤对湿扩散的影响。建立了纤维周期排布、随机排布、界面相损伤随机分布3种细观有限元模型。用上述模型分析了单向复合材料横向有效湿扩散系数(TEMDUC)随纤维和界面相体积分数、湿扩散性能以及界面相损伤率变化的规律,理论预测与有限元计算结果一致。研究发现:界面相或纤维相的扩散系数存在一个临界值,当扩散系数小于该临界值时,TEMDUC随纤维体积分数的增大而减小;反之,TEMDUC随纤维体积分数的增大而增大,此临界值的大小与纤维体积含量无关。研究还发现纤维界面损伤率相同的条件下,其分布的随机性对复合材料的有效湿扩散系数影响不大。 Based on the Halpin & Tsai model, a wet diffusion model of three-phase composites considering the fiber / matrix interface phase was developed through the governing equations of wet diffusion and heat conduction and the boundary conditions of the composites. The effects of random damage at the fiber interface on wet diffusion Impact. Three kinds of mesoscopic finite element models were established, including periodic arrangement of fibers, random arrangement and interphase damage. The above model was used to analyze the regularity of transverse effective wet diffusion coefficient (TEMDUC) with the change of volume fraction, wet diffusion and interfacial phase damage rate of the unidirectional composites. The theoretical predictions are consistent with those of the finite element method. It is found that there is a critical value for the diffusion coefficient of interfacial phase or fiber phase. When the diffusion coefficient is smaller than the critical value, TEMDUC decreases with the increase of fiber volume fraction. On the contrary, TEMDUC increases with the increase of fiber volume fraction , The size of this threshold has nothing to do with the fiber volume content. The study also found that under the same condition of fiber interface damage, the randomness of the distribution has little effect on the effective wet diffusion coefficient of the composites.