基于弹性节点三维结构模型的电磁屏蔽服装屏蔽性能理论研究

Electromagnetic shielding (EMS) garment has important and broad demand, but its shielding effectiveness has not been clarified at present. The bottleneck problem is that the electromagnetic field distribution rule are still unclear when the electromagnetic waves enter into the EMS garment. This project constructs a three-dimensional structural model of the garment based on the elasticity node according to the morphological characteristics of human body. The structural model is made grid partition using the secondary spatial partition method. Grid electromagnetic parameters are obtained combining with the equivalent medium inversion method, the coaxial transmission / reflection method and the numerical simulation method. The perfectly matched layer is selected as absorbing boundary conditions to build a physical model of the EMS garment. The physical model is made numerical simulation and calculation by MATLAB according to the finite difference time domain method. Combining with the testing validation, the distribution variation of the electromagnetic field is revealed when the electromagnetic waves with different frequencies enter into the garment at different locations. The influencing rule and mechanism of the related parameters of the garment style, hole location, stitch, fabric, and the emission source location, frequency, polarization direction on the spatial distribution of the various parts of the garment are determined. Then an evaluation model of the overall SE of the EMS garment are constucted. Finally, the experimental platform is build to test the EMS garment according to the national standard. The theoretical results of each stage are constantly contrasted, verified and improved. This study can provide a theoretical basis for the design, production, testing and evaluation of the EMS garment.

电磁屏蔽服装有着重要和广泛的需求，但其屏蔽性能目前还未弄清，瓶颈是电磁波入射时服装内部电磁场强空间分布规律还未明确。本项目根据人体形态特征构建基于弹性节点的服装三维结构模型，采用二次空间非均匀法对该模型划分网格，结合等效介质反演法、同轴传输/反射法及数值模拟等方法获取网格电磁参数，选择完全匹配层为吸收边界条件，从而建立电磁屏蔽服装的物理模型。根据时域有限差分法采用MATLAB对物理模型进行数值模拟及计算，结合实验验证以揭示不同参数电磁波入射时电磁屏蔽服装内部电磁场强的空间分布变化规律，明确款式、面料、开口、缝迹、其它孔缝、发射源极化方向、频率及位置等因素对服装内部电磁场强空间分布的影响规律及影响机理，并建立电磁屏蔽服装整体屏蔽性能的评价模型。进一步根据国家标准搭建实验平台对电磁屏蔽服装进行测试，不断对比、验证及完善各阶段理论成果。本研究可为电磁屏蔽服装的设计、生产、测试及评价提供理论依据。

电磁屏蔽服装在各行业有着重要和广泛的需求，但其屏蔽性能变化规律及机理目前还未弄清，为此本项目开展了基于弹性节点三维结构模型的电磁屏蔽服装屏蔽性能相关理论研究：1)结合计算机拟合及识别技术构建描述服装整体形态的空间曲线，通过分析服装特征及服装结构获取弹性节点，从而建立了可精确描述服装并且适合电磁分析的弹性节点三维结构模型。2)提出了针对该模型的二次空间非均匀网格划分等算法，发明了获取面料、拉链、线缝等区域电磁参数的多种方法，从而构建了适合电磁分析的服装三维物理模型。通过明确该物理模型边界条件、约束条件、激励源等参数的设定方法，最终建立了基于时域有限差分法的电磁屏蔽服装内部电磁场强空间分布的数值模拟及数值计算方法。3)结合上述理论计算与实验验证，揭示了款式造型、面料、开口、线缝、发射源极化方向、距离、频率及测试位置等因素对服装内部电磁场强空间分布的影响规律及影响机理，发现了多层面料、线缝、开口区域等参数使服装防护效果下降的现象并对其形成原因进行了机理分析，探索了采用吸波材料提升服装整体屏蔽性能的方法，从而提出了基于上述理论的服装设计及制作原则。4)明确了服装各个参数及发射源相关参数与服装屏蔽效能之间的关联及规律，揭示了多种要素综合作用下电磁屏蔽服装整体屏蔽性能指标的变化规律及机理，提出了危险频点等相关概念和指标，从而建立了基于多指标综合评价的电磁屏蔽服装评价模型。项目的研究成果可对电磁屏蔽服装的设计、生产及评价提供有力参考，丰富了类似服装特征的柔性电磁屏蔽防护产品的电磁计算方法及分析理论，部分成果已在企业进行转化，因此具有重要的科学意义及应用价值。