Strong Electromagnetic Pulse With The Distributed Array Apertures Chassis Damage Effect Study

In the modern war background, the electronic disturbing and protection are becoming increasingly fierce. After decades of development, the strong electromagnetic pulse technology has gradually matured. Electromagnetic pulse(EMP) can be produced by nuclear explosions, lightening, high-power microwave bomb, electromagnetic pulse bombs and other methods, which can damage the crystal diodes, transistors, integrated circuits, resistors and capacitors, filters, relays and other components used in electronic equipments. Electromagnetic pulse bombs have become a fatal weapon in the modern war.The coupling mode of Electromagnetic pulse includes "front-door coupling" and "back-door coupling." The energy generated by the "front-door coupling" may be separated by system's protection devices, which will not interfere with or damage systems generally. The necessary apertures on the shielding box are used to connect wires, dissipate heat, transmit information, etc. Electromagnetic pulse coming through these apertures will significantly interfere with the working electronic devices and may damage them. The duty of this paper is to study the damage effects of Electromagnetic pulses on shielding boxes with array distributed apertures.The effects of array type, aperture number, rising time, aperture thickness, distance of aperture centers and array offset with same aperture area on the electronic field intensity of box center and aperture centers were simulated using XFDTD software.The results from the simulation show that,in the unaffected shielding effectiveness circumstancses,we can consider a regular polygon and symmetric distribution of the apertures arrays instead of part of the aperture array,which also avoids the hole on the box too large to ensure the structural strength of the cabinet. If we need to significantly reduce the aperture coupling of electromagnetic pulse energy and arrang the aperture arrays by the vertical symmetry,then the box center's maximum Electric field and the maximum power density has a logarithmic relationship with the rise time respectively.when the contradictions exist in the heat sheidld cavity and electromagnetic shielding problems,the most effective way is increasing the thickness of surface,while increasing the maximum size of the hole. When hole array in the horizontal and vertical directions are offset,the maximum field strength box center offset a cubic change,and on ehe offset center of symmetry.It has a better shielding effect for using the circle hole and rectangular hole mixing matrix array instead of a single pass of the holes.This paper mainly studied the damage effects of PCB by Gaussian pulse coupled into the box,engendering the power density and energy.The results from simulation show that,different field strength incident on the maximum power density values, the rise time of different situationgs in different critical damage incident field of arbitrary intensity and coupled to the internal relationship between the cabinet and infered a related formula,the error can be controlled in 2% in a large range.in addition,it also studied in the direction of zhe incident field coupling into the box on the internal field. Further study of the PCBboard inside the case of semiconductor components in the electromagnetic couping of the energy generated damage.