电磁层析成像金属探伤传感系统的仿真研究

摘要

为对电磁层析成像金属探伤传感系统进行正问题的求解和三维仿真研究,建立了电磁层析成像用于金属探伤的数理模型,并采用有限元电磁仿真软件ANSOFT MAXWELL对金属探伤的环绕式传感阵列进行了三维仿真并分析了激励频率、提离高度、裂纹深度和长度、待测材料的电导率和磁导率等参数对检测结果的影响.仿真结果表明,传感系统的激励频率应设置在500Hz到5KHz之间和提离高度应设置在0.2mm到1mm之间,该仿真分析对实际传感系统的设计以及图像重建算法的开发都具有指导意义.%To solve the forward problem and do the 3D simulation research for the electromagnetic tomography metal detection sensing system,the mathematical and physical models for the electromagnetic tomography sensing system for metal flaw detection is constructed firstly.In the later simulation,the finite element software ANSOFT MAXWELL is adopted to carry out the three-dimensional simulation and analyze on the wraparound sensor array.The key factors including exciting frequency,lift-off height,depth and length of crack,and the conductivity and permeability of the material to be detected,and proved to have impact on the output signal to different extents.The coil-all-around sensing structure for the EMT crack detecting system is proposed with exciting frequency ranged from 500 Hz to 5 KHz and lift-off height ranged from 0.2mm to 1mm.The simulation and analysis is instructive in both the designs of the actual sensing system and the later image reconstruction algorithm.