基于屏蔽纤维空间离散微介质灰度模型的电磁屏蔽织物吸收、反射及透射特性分析与调控方法研究

Electromagnetic shielding fabric (EMSF) with absorbing characteristic is a new artificial electromagnetic media with wide application. Until now the mechanism, rule and regulation method of the absorption, reflection and transmission characteristic of the EMSF are not clear and are theoretical problems to be solved. In this project, the shielding fibers are separated into micro-mediums with different electromagnetic parameters by gray recognition, multilayer fusion and segmentation algorithm using scanning electron microscopic imaging and three-dimensional calibration technology. A space discrete micro-medium gray model which can accurately describe the complex arrangement of the shielding fibers is built. The model is made three-dimensional grid partition and made secondary classification numerical calculation and simulation using finite difference time domain method. The relevant electromagnetic parameters of the whole fabric and the region medium are determined combined by the inversion theory of the equivalent medium and the experimental verification. The influence rule and mechanism of the compatibility and arrangement of the shielding fibers on the absorption, reflection and transmission characteristic of the EMSF are revealed. The influencing law and quantitative relationship between the structure parameters and the absorption and reflection characteristic of the fabric are analyzed and the regulation methods are constructed. A number of the EMSF samples are manufactured using fabric loom to analyze the compatibility and the arrangement of the sheilding fibers. The absorption, reflection and transmission related parameters of the samples are tested. The experimental results are compared with the calculations to verify and improve the theoretical results. The researches in this project can provide a theoretical basis for the design, production, and evaluation of the new EMSF.

具有吸波特性的电磁屏蔽织物是用途广泛的人工新型电磁介质，到目前其吸收、反射及透射特性的发生机理、规律及调控方法还未明确，是亟待解决的理论课题。本项目使用扫描电镜成像及三维显微标定技术，采用灰度识别及多层图像融合算法，将屏蔽纤维离散成电磁参数不同的微介质，构建可精确描述织物内屏蔽纤维复杂排列形态的空间离散微介质灰度模型。对该模型进行三维网格划分并采用时域有限差分法进行二次分级数值计算及仿真，结合等效介质反演理论及实验验证确定区域介质、整体织物的相关电磁参数，从而揭示屏蔽纤维配伍及排列形态对电磁屏蔽织物吸收、反射及透射特性的作用机理及影响规律，据此分析结构参数对织物整体吸收及反射特性的影响规律、量化关系并建立调控方法。采用小样织机织造样布并分析屏蔽纤维配伍及排列形态，测试其吸收、反射及透射相关参数，以不断对比验证及完善各阶段理论成果。本项目可为新型电磁屏蔽织物的设计、生产及评价提供理论依据。

电磁屏蔽织物用途广泛，但目前主要依靠反射电磁波达到屏蔽目的，会对环境产生二次电磁污染及电磁干扰，并易在成型腔体内因多次反射而形成对防护不利的电磁场强增强效应，严重制约了电磁屏蔽织物的应用。为此本项目开展具有吸波特性的电磁屏蔽织物相关理论问题研究，探索其吸收、反射及透射特性的发生机理、规律及调控方法。1)构建了可精确描述织物内各种屏蔽纤维复杂排列形态的空间离散微介质灰度模型，提出了科学描述屏蔽纤维复杂排列形态的多个参数，为电磁屏蔽织物相关数值计算、机理分析奠定了基础；2)提出了适合空间离散微介质灰度模型的三维网格划分、边界条件等参数设定等方法，发明了织物微观区域的电磁参数测定及获取方法，建立了基于FDTD的吸波型电磁屏蔽织物数值计算理论，为电磁屏蔽织物的电磁计算提供了新路径，也为相关规律及机理研究提供了依据；3)揭示了反射型、吸波型屏蔽纤维配伍及空间排列形态对电磁屏蔽织物吸收、反射及透射特性的作用机理及影响规律，发现了屏蔽纤维配伍、排列形态及含量，以及织物密度、紧度、组织结构、层数等重要结构参数对织物整体吸收及反射特性的影响规律，为吸波型电磁屏蔽织物的相关理论研究以及产品研发提供了基础；4)建立了基于结构参数的吸波型电磁屏蔽织物调控方法，发现了石墨烯纤维、碳纳米管纤维、碳纤维、铁氧体、聚苯胺等材料在电磁屏蔽织物性能提升中的作用机制，为吸波型电磁屏蔽织物的设计、生产及评价提供了理论参考。项目的研究成果具有显著的科学意义及应用价值，对吸波型电磁屏蔽织物的相关理论研究、新产品开发、实际生产等方面均具有良好的指导作用。