远场涡流检测中的相速度分析

对远场的相速特性作了较详细的分析。文中首先从电磁场有限元出发对轴向和径向上的似稳态场相速度作了仿真研究，发现其在空间某些位置上具有稳定的相速，与波特点相似。同时分析了参数μ，σ，ｆ对相速的影响。结果表明，其与电磁波在良导体中传播规律的定性分析相符。最后本文还对瞬态激励下的远场涡流效应作了一定分析，结果再次证明其具有似波特性。

Analysis of Phase Velocity in Remote Field Eddy Current Inspection

in the recent study on the inspection technique of remote field eddy current(RFEC) the characteristics of wave-like phenomona have been paid much attention. In this paper the property of phase velocity in RFEC has been analyzed in detail. First, phase velocitysimulation is done in axial and radial directions in quasi--steady field through the finite elementmethod of electromagnetic (EM) field. Constant velocity at some position in the space is foundto be similar to the wave property. Analysis on the influence of parameters U,a and f on phasevelocity shows that it likes that of EM wave propogation in good conductor. Finally the RFECeffect excited by a transient source also shows the wave--like characteristic. The research ishelpful to the RFEC mechanism research and practical use.