中文摘要：

建立了填充椭球颗粒电磁屏蔽复合材料等效电磁参数的物理模型，基于变分原理和电磁波传输理论推导出其电磁屏蔽性能的预测公式，计算了不同填充条件下复合材料的屏蔽效能及反射率，分析了填料显微结构特征（浓度、形状、尺寸、分布方式）对复合材料屏蔽性能的影响规律．结果表明，复合材料屏蔽效能和反射率随填料填充浓度、长径比的增加而增大；针形和片形填料优于球形填料且定向分布好于随机分布；材料的反射率在特定的填充浓度及填料尺寸下存在峰值．屏蔽效能的计算结果与实验上填充球形银包羰基铁和镀镍短碳纤维的屏蔽复合材料的测试数据拟合较好。

英文摘要：

The effective electromagnetic parameters physical model of composites with ellipsoidal particles was established and prediction formulas of composites＇ shielding properties were derived based on variational principle and electromagnetic wave transmission theory. The shielding effectiveness and refiectivity of composites under different filling conditions were calculated and the influence laws of fillings＇ microstructure characters （concentration, shape, size and distribution mode） to shielding properties of composites were investigated. The shielding effectiveness and reflectivity of composites improve with the increase of concentration and aspect ratio of fillers, the needle and flaked fillers are better than spherical fillers and the directional distribution is better than random distribution, the reflectivity of composites in certain concentration and size of fillers exists peak value. The shielding composites with spherical carbonyl iron and nickel-plated short carbon fibers were prepared and the results of the numerical calculation of shielding effectiveness are in good agreement with the experiment data, the validity of proposed scheme was verified.