涡流效应对脉冲漏磁检测信号的影响

The Influence of Eddy Current Effect on Pulsed Magnetic Flux Leakage Testing Signal

为了研究脉冲漏磁检测中涡流效应对漏磁信号的影响,应用有限元分析软件建立了脉冲漏磁检测仿真模型,对被测样本内磁场与涡流分布随时间变化的情况进行了分析,进而研究了基于不同激励电压和磁芯磁导率仿真模型的漏磁信号波形。仿真结果表明,当磁场激励较小时,漏磁信号在脉冲激励电压的上升阶段存在过冲现象,随后达到稳态。搭建了检测平台进行检测试验,检测结果与仿真结果相一致,研究表明在缺陷检测中应用检测信号峰值特征评估缺陷深度的方法具有更高的精度。

In order to study the influence of eddy current effect on leakage magnetic field signals in pulsed magnetic flux leakage testing,this paper uses the finite element analysis software to establish simulation models for pulsed magnetic flux leakage testing,analyses the distributions of magnetic field and eddy current in the steel plate sample,and analyses the leakage magnetic field signals under the conditions of different excitation voltage and magnetic core permeability.Simulation results show that when the magnetic field excitation is weak,the leakage magnetic field signal has overshoot in the rising phase of the pulsed excitation voltage,and then reaches the steady state.The experimental detection platform is built and experimental results are in agreement with simulation ones.The research shows that using the peak feature of detection signals to evaluate the depth of the flaw in the defect detection has higher accuracy.