基于连通磁路的脉冲远场涡流传感器设计及缺陷定量评估与分类识别

摘要

为了克服传统脉冲远场涡流传感器由于结构的限制带来的激励磁场在空间出现发散、对大壁厚管道检测能力较弱以及难以对缺陷进行准确定位的问题,在分析了脉冲远场涡流检测原理的基础上,采用仿真与实验相结合的方法,仿真分析了基于连通磁路的脉冲远场涡流传感器的聚磁效果,研究了该传感器对管道轴向内外壁裂纹缺陷的定量评估能力,比较了检测线圈处于不同位置时的缺陷分类识别效果.仿真结果表明,该传感器通过引导磁场的定向传播实现了对磁场的聚集,同时,通过提取适当检测位置的信号负峰值可以实现对缺陷的分类识别.最后,采用实验的方法验证了基于连通磁路的脉冲远场涡流传感器对管道轴向裂纹缺陷深度的定量能力,实验结果表明该传感器可以很好的实现对缺陷的定量评估.%To overcome the problems of radiating of exaction magnetic field in space by the traditional pulsed remote field eddy current(PRFEC)probe,the reduction of detecting ability for big thickness pipeline and the restriction of locating position of defect. On the basis of analyzing the principle of PRFEC, the forcing magnetic field effect of the PRFEC probe with the connected magnetic core (CMC) is analyzed by the method of finite element simulation and experiment. Then, the defect quantification ability of this probe is researched, and the classification effect is analyzed when the detecting coil locates in different positions. The simulation results show that the CMC PRFEC probe focuses the magnetic field going downwards through the conducting wall, the negative peak can be extracted to classified the defect. Finally, the performances of quantifying the axial defect depth by the connected magnetic core PRFEC probe are investigated by experiment, results show that the probe can be used to quantify the defect.