管板焊缝结构涡流检测端部效应抑制仿真试验

Simulation Research on Restraining End Effect of Eddy Current Testing for Fillet Welds in Tube Sheets

针对管板角焊缝结构涡流检测的特点,研究了影响常规涡流检测实施的相关因素(包括外形、材料等),并在此基础上采用ANSYS有限元仿真技术对专用的传感器进行了优化设计,增加了永磁磁化单元,结合抑制涡流检测端部效应的信号处理方法,减小了端部检测盲区范围,提高了焊缝缺陷的检测精度。仿真和试验结果表明,通过对管壁和焊缝施加磁化及对检测信号进行差分处理,能够实现薄壁管管板角焊缝深层缺陷的检测,证明了管板焊缝结构涡流检测的可行性,提高了管板涡流检测的效率。

In view of the characteristics of eddy current testing of fillet welds in tube sheets,the relevant factors affecting the implementation of conventional eddy current testing（including shape,material,etc.）are investigated.On this basis,the ANSYS finite element simulation technology is used to optimize the design of the special sensor.The permanent magnet is added,and the signal processing method of restraining the end effect of eddy current testing is adopted,thereby reducing the range of the end detection dead zone and improving the detection accuracy of weld defects.The simulation and experimental results showed that it could realize those deep defects detection in the fillet weld of thin-walled tubes plate when magnetization was applied to the pipe wall and differential processing means was undertaken for the detection signals,proving the feasibility of eddy current testing for the tube plate welding structure and improving the detection efficiency.