基于有限元仿真和数据拟合的管道缺陷量化分析方法

Analysis Method for Defect Quantification of Pipeline Based on Finite-element Analysis Simulation and Data Fitting

针对管道漏磁内检测中的缺陷量化问题,根据安培环路定理、磁通连续性定理及柱坐标变换建立了缺陷漏磁场的数学模型。以有限元仿真分析软件得到的矩形缺陷数据为研究对象,得到缺陷尺寸与漏磁信号特征值的回归方程,运用最小二乘曲线拟合方法对仿真数据进行拟合。误差分析结果表明:轴向一次方程和轴向径向一次方程能更准确地计算缺陷长度,轴向径向二次拟合方程能更准确地计算缺陷深度,为管道漏磁内检测缺陷量化提供了可靠的分析方法。

In order to solve the defect quantification problem of pipeline in magnetic flux leakage inner detection for pipeline,a mathematical model of MFL field was built based on ampere circuital theorem,flux continuity theorem and cylindrical coordinate transformation.The rectangular defect data of magnetic flux leakage inner detection for pipeline obtained by finite element simulation analysis software were taken as research object,and the regression equations with defect size and magnetic flux density characteristics were established.The fitting of the equations for simulated data was realized with the least square curve fitting method.The error analysis indicated that axial linear equation with axial and radial linear equation could more accurately calculate the defect length,while axial and radial two fitting equations could accurately calculate the defect depth.The present research provided reliable analysis method for the defect quantification in magnetic flux leakage inner detection for pipeline.