脉冲涡流解析模型研究  

Analytical modeling for pulsed eddy current testing

作　　者：范孟豹[1] 黄平捷[1] 叶波[1] 侯迪波[1] 张光新[1] 周泽魁[1] 

机构地区：[1]浙江大学工业控制技术国家重点实验室,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2009年第9期1621-1624,共4页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(50505045);国家教育部博士点基金资助项目(200803350058)

摘　　要：研究任意层平板型导电结构脉冲涡流(PEC)差动探头输出信号的解析模型.建立谐波激励下探头阻抗的解析模型,并将探头阻抗解析模型由二重积分转化为定积分,大大减小了计算量;采用有限项傅里叶谐波近似脉冲信号,建立差动探头等效电路,从而应用叠加原理以仿真电压脉冲激励下探头的输出信号.为了验证模型的有效性,针对导电结构厚度检测问题进行仿真与实验测量.计算结果与实验结果吻合良好,表明研究结果是正确的.研究的脉冲涡流探头输出解析模型可用于理解脉冲涡流检测机理、构建探头响应仿真器和改进反演算法.Analytical modeling for response of differential probes placed above arbitrary number of parallel nonferrous stratified conductive structures for pulsed eddy current （PEC） testing was studied. The closed- form solution to the impedance of probe supplied with harmonic excitation was presented. Then the model was transformed from double integral into definite one for significant reduction in computation time. The finite Fourier series expansion was formulated to approximate the pulse excitation and the equivalent bridge circuit of differential probes was developed in order to apply superposition principle for simulating the response of differential probes driven by voltage pulse. Simulations and experiments on thickness of nonferrous conductive specimen were conducted to verify the model. The calculated results agreed with the measured results. Results show that the developed model is effective. The model can be used to grasp the essence of PEC testing, create a simulator of probe response and improve the inverse algorithms.

关 键 词：脉冲涡流检测 傅里叶级数 解析模型 导电结构 厚度测量 

分 类 号：TM154[电气工程—电工理论与新技术] TP216[自动化与计算机技术—检测技术与自动化装置]