铁磁构件表层裂纹漏磁场分析及检测系统

Nalytical study on crack magnetic flux leakage for ferromagnetic component and detection system based on geomagnetic field

针对铁磁构件裂纹损伤检测方法和仪器应用技术现状,建立了V型裂纹漏磁场分析模型,得出了平板铁磁构件表面指定探测点的漏磁场理论表达式。采用MATLAB软件编程进行全面的仿真分析,得出了漏磁场的法向分量与裂纹开口宽度的关系曲线、漏磁场的法向分量与裂纹深度的关系曲线、漏磁场的法向分量与裂纹长度的关系曲线;得出裂纹漏磁场法向分量过零点、漏磁场垂向分量出现最大值和漏磁场切向分量出现裂纹端部过零点的漏磁场分布特性。根据理论分析得出的裂纹漏磁场特征,设计制作了阵列式的裂纹检测装置和检测平台,并对带有V型裂纹的平板铁磁构件进行检测。实验表明:文中理论分析得出的三维漏磁场与检测结果能够较好的吻合,并对裂纹的几何参数估计具有一定的指导意义,根据漏磁模型研制的检测装置能探测铁磁构件的裂纹缺陷。

Based on technical aspects of ferromagnetic components crack damage detection methods and instruments applications, this paper establishes a the magnetic flux leakage analysis model for V-Cracks to get the theoretical expressions for any probe point of flat ferromagnetic component surface. We use MATLAB software programming to do a comprehensive simulation, and obtain the relation curve between magnetic flux leakage normal component Hy and crack opening width, the relation curve between magnetic flux leakage normal component Hy and crack depth, the relation curve between magnetic flux leakage normal component Hy and crack length are obtained, crack magnetic flux leakage distribution characters： normal component of Hy with zero-crossing, maximum value of tangential component Hx, and tangential component Hz with tip zero-crossing. According to the leakage magnetic characteristics obtained underby the theoretical analysis, the array type detection device and test platform are designed and fabricated, and then the plate-type ferromagnetic component with V-Cracks is detected. The experimental results show that： there is a good agreement between the three-dimensional magnetic flux leakage obtained from thesis theoretical analysis and the test results, to a certain degree the magnetic flux leakage model has directive significance for the prediction and analysis of crack parameters, and the test device be developed according to the magnetic flux leakage model is able to detect cracks in ferromagnetic components.