建筑墙体对电磁脉冲响应的FDTD分析

 采用时域有限差分法和傅里叶变换对电磁脉冲作用于建筑墙体后发生的反射和透射进行了比较全面的研究分析。采用周期边界实现了不同建筑墙体对电磁脉冲响应的数值计算，对计算的结果进行了讨论分析，研究结果表明：钢筋阵对低频段的屏蔽效果很好，当频率增加时，屏蔽效果变差。混凝土墙的频域波形具有明显的周期性，存在许多谐振频率，谐振时透过很大，谐振频率由墙的厚度、磁导率和介电常数决定，要提高墙的屏蔽效果必须增加墙的电导率，以达到一个比较好的屏蔽效果。钢筋混凝土墙的屏蔽效果和反射特性由钢筋和混凝土墙共同调制决定。

Response of electromagnetic pulse penetrating through building walls

The response of electromagnetic pulse penetrating building walls is analyzed using FDTD and Fourier analysis method. The pulse responses within a wide frequency band are calculated based on periodic boundary condition and Gaussian pulse. Through the discussion of the calculated results, the influences of different walls are obtained, which will improve the electromagnetic shielding design to protect electronic equipments. The simulation results show that the rebar array works pretty well for shielding in low frequency, but the shielding effectiveness will become poor as the frequency increases. The periodicity of the frequency domain waveform in concrete walls indicates that there exists a lot of resonance frequency points and the transmission coefficients become comparatively higher on these resonance frequency points. The resonance frequency is determined by the thickness of the wall, the permeability and the dielectric constant. The conductance of walls must be increased for improving shielding effects to a desired level. Reinforce concrete wall shielding effectiveness is determinded by the concrete wall and the rebar.