强磁场对引信的危害以及屏蔽效果的研究
毕业论文关键字 电磁屏蔽，电磁轨道炮，被动屏蔽，双指数磁场, COMSOL Multiphysics
Title Research on Damages Suffered by Fuzes and Shielding
Effectiveness in High Magnetic Field
Abstract This paper researches the electromagnetic shielding of fuzes under the launching environment of the electromagnetic railgun. The shielding of low-frequency and high-intensity electromagnetic waves emerged during the railgun operation are studied by the COMSOL Multiphysics simulation software.In a first phase, this paper mainly studies the basic theory of electromagnetic shielding, including the development of shielding technology;In a second phase, the electromagnetic railgun is introduced and its working principle and the magnetic field distribution are analysed.As a consequence,the current is approximated by a double- exponential function which will be analysed by the MATLAB software;In a third phase, shielding mechanism and the passive shielding including the shielding material and the shielding layers are summarized by the paper.What’s more, application of the transmission line theory in the electromagnetic field and the electromagnetic shielding effectiveness are discussed in the third part.In a fourth phase, the simulation models are established.And the paper mainly analyses shielding in the frequency domain,magnetostatic domain and the case of a double- exponential-shaped magnetic field in the time domain. The results will be revealed.Finally,some remarks and conclusions are made.
Keywords Electromagnetic shielding,Electromagnetic railgun, Passive shielding, Double- exponential-shaped magnetic field, COMSOL Multiphysics
目 次
1 引言 1
1.1 研究内容及目的 1
1.2 电磁场理论的建立 1
1.3 电磁屏蔽概念 4
1.4 电磁屏蔽技术的发展 4
2 电磁轨道炮原理及环境分析 5
2.1 电磁轨道炮简介及发展 5
2.2 电磁轨道炮工作原理 9
2.3 电磁轨道炮磁场分析. 10
2.3.1 脉冲电流. 12
2.3.2 双指数电流频域分析. 15
3 强磁场屏蔽. 16
3.1 基本的屏蔽机理. 16
3.2 主动屏蔽. 16
3.2 被动屏蔽. 17
3.2.1屏蔽原理 . 17
3.3 屏蔽材料. 19
3.3.1 铁电材料. 20
3.3.2 导电性材料和铁磁性材料. 20
3.3.3 薄膜和导电涂料. 22
3.3.4 其他材料. 23