小径管周向裂纹脉冲涡流检测仿真和试验研究

针对小径管周向裂纹缺陷，通过有限元仿真及试验，研究了利用磁导体环形激励脉冲涡流检测技术检测小径管周向裂纹缺陷的问题。仿真给出了管道在有缺陷和无缺陷状态下磁场分布、涡流分布以及接收线圈的电压值。从仿真结果可以观察出，周向裂纹端头处的磁场分布以及涡流分布会发生明显变化，产生沿管壁法向的磁场，检测线圈位于裂纹端头处正上方时检测灵敏度最高。实际检测结果与仿真结果一致，表明磁导体环形激励轴向涡流对小径管周向缺陷具有显著的检测效果。

Simulation of Circumferential Crack Pulsed Eddy CurrentTesting in Small Diameter Tube

For small diameter pipe circumferential crack detection problem, do the finite element simulation.Utilize an magnetic conductor coil axial eddy current test to detect small diameter tube circumferential crack defect.The simulation shows magnetic field distributions eddy current distribution and the receiving coil voltage,when pipeline in the case of defects and defect-free state.From the simulation results can be observed that the magnetic field and eddy currents distribution of circumferential cracks at the ends changed significantly, and generating a magnetic field along the normal to the wall.The induced voltage reaches the maximum value when the detection coil just above the ends of the crack.The actual testing results are in accordance with the simulation results,showing that magnetic conductor coil axial eddy current technique for small diameter pipe circumferential defect detection effect is remarkable.