燃气管道电涡流裂纹检测仿真研究

Simulation Research on Eddy Current Crack Detection of Gas Pipeline Based on Comsol Multiphysics

燃气管道外表面疲劳裂纹是可能导致管道断裂的危害性缺陷。通过有限元仿真与实验研究,研究利用多频涡流检测技术使用柔性阵列式探头检测以4340#钢为材料的管道外壁疲劳缺陷问题。仿真给出不同物理参数的管道涡流分布、磁场分布及其变化。从仿真结果可观察出,管壁涡流疲劳裂纹检测结果并非与输入激励频率成正相关,而是针对不同金属材料具有最优参数。涡流检测提离值与磁场强度成负相关。涡流场的分布及其变化规律与磁场情况类同。据此可知检测管壁疲劳裂纹时依据金属材料选定最优物理参数进行检测可有效提高管壁涡流疲劳裂纹检测质量。实验研究结果与仿真结果一致,并且得出以4340#钢为材料的管壁疲劳裂纹涡流检测最优参数,对于涡流无损检测性能的优化提高具有一定的参考价值。

Fatigue cracks on the outer surface of gas pipelines are harmful defects that may cause pipeline fracture.Through finite element simulation and experimental research,the multi-frequency eddy current testing technology was used to detect the fatigue defect of the outer wall of the pipeline with 4340#steel using a flexible array probe.The pipe eddy current distribution,magnetic field distribution,and its changes with different physical parameters were given by simulation.It can be observed from the simulation results that the eddy current fatigue crack detection results of the tube wall are not positively correlated with the input excitation frequency,but have optimal parameters for different metal materials.The eddy current detection liftoff value is inversely related to the magnetic field strength.The distribution of the eddy current field and its variation law are similar to those of the magnetic field.According to this,it can be seen that the detection of the optimal physical parameters of the metal material when detecting the fatigue crack of the pipe wall can effectively improve the quality of the eddy fatigue crack detection of the pipe wall.The experimental results are consistent with the simulation results,and the optimal parameters of tube wall fatigue crack eddy current detection using 4340#steel are obtained,which has a certain reference value for the optimization of eddy current non-destructive testing performance.