铁磁材料脉冲涡流厚度检测中的边缘效应  

Edge Effect in Pulsed Eddy Current Detecting for Ferromagnetic Materials

作　　者：王健[1] 滕永平[1] 傅迎光[1] 孙明璇[1] 刘再斌[2] 范智勇[2] 石坤[2] 

机构地区：[1]北京交通大学物理系,北京100044 [2]中国特种设备检测研究院,北京100013

出　　处：《无损检测》2013年第8期54-60,共7页Nondestructive Testing

基　　金：国家质检总局科研专项基金(201110028-04)资助项目

摘　　要：当探头位于被测试件的边缘时,试件与理想模型存在着偏差,这种偏差会导致测量误差。根据脉冲涡流检测的工作原理,数值仿真了探头位于铁磁试件边缘的不同位置时试件厚度与提离高度对厚度测量的影响。结果表明:数值仿真和试验结果的一致性较好;探头处于试件的边缘时,测量值总比试件的实际厚度小;试件厚度和提离高度越大,测厚的误差也越大;探头处于试件角区比处于远离角区的一般边缘,测量误差要大一倍左右。为了减少边缘效应引起的测量误差,最后给出了根据测量厚度和提离高度计算试件实际厚度的拟合公式。When the probe is on the edge of the specimen, ,here are some devlanons between m~ i the specimen, which result in the measurement error. Based on the PET detecting principle, effects of the spectmen thickness, lift-of{ height on the measurements are numerically simulated when the probe is on the edge of ferromagnetic specimens, and are compared with experimental results. The results show that the numerical simulations are well consistent with that obtained in the experiments. The measurements values are always smaller than the actual thicknesses when the probe is on the edges of the speeimens. The measurement errors increase with the increases of the thickness and the lift-off height. The relative error obtained using the probe in the specimen corner area is about twice that using the probe in the general edge away from the corner area. In order to reduce the measurement error caused by the edge effect, fitting formulas are finally given, by which the actual specimen thickness can be obtained using the measured thickness and lifvoff height.

关 键 词：脉冲涡流检测 铁磁介质 测厚 特征衰减时间 边缘效应 

分 类 号：TG115.28[金属学及工艺—物理冶金]