管道内壁腐蚀缺陷涡流检测仿真研究

Simulation Research on Eddy Current Testing of Inner Surface Corrosion Defects in Pipeline

在管道内壁缺陷检测中,传统响应分析对典型坑状缺陷特征参数的测量存在一定的局限性。针对固定直径和深度的圆柱形腐蚀缺陷的响应问题,创建了管道内壁腐蚀缺陷三维有限元模型。根据趋肤深度效应确定管道仿真的最佳频率,通过ANSYS软件进行管道的电磁场仿真,得到涡流与磁感应强度分布图。在MATLAB里将仿真的阻抗数据进行拟合,分析出阻抗相位和幅值随腐蚀深度变化的近似规律。仿真研究表明,随着缺陷深度的加深,阻抗幅值与腐蚀缺陷具有一定的线性正比关系。线圈探头和管道及内壁缺陷三者的仿真新模型的建立,为管道腐蚀缺陷数据定量化检测开辟了新道路。

In the study on the surface defects in the pipeline, the traditional response analysis has some limita- tions on the measurement of typical pit defects. In order to solve the problem of cylindrical corrosion defects with fixed diameter and depth, a three-dimensional finite element model of pipe inner wall corrosion defects was established. According to the skin depth effect, the optimal frequency of pipeline simulation was determined. The electromagnetic field simulation of the pipeline was carried out with ANSYS software, and the distribution of eddy current and magnet- ic induction was obtained. Based on MATLAB, the simulated impedance data were fitted to analyze the approximate law of the impedance phase and amplitude with the change of corrosion depth. The simulation results show that the impedance amplitude has a certain linear relationship with the corrosion defect with the depth of the defect. The es- tablishment of the new models for coil probe and pipeline and the internal surface defects , open up a new way for the quantitative detection of pipeline corrosion defect data.