弱磁检测漏磁信号影响因素实验与仿真研究

Experiment and Simulation Research on Influencing Factors of Flux Leakage Signal in Weak Magnetic Field Detection

弱磁检测能够有效地发现钢筋、钢绞线等铁磁构件因锈蚀产生的结构受损;但是这些铁磁材料会因所在地点、所受地磁场磁化时间的不同,从而使其在弱磁检测中所受的地磁场强度与自身磁化程度也不同。所以,为了探究地磁场与自身磁化对采集到的漏磁信号是否存在影响,在此通过磁屏蔽与退火的方法控制地磁场与自身磁化强度两个变量,进行漏磁信号检测对比实验。为了进一步分析实验结果,采用COMSOL软件对实验进行仿真模拟。结果表明:地磁场对漏磁信号只存在数值上的影响,不会明显改变漏磁信号的变化规律;而自身磁化才是影响漏磁信号规律的主要因素。与此同时,仿真结果也与实验结果保持一致。

Weak magnetic field detection can effectively discover the structural damage caused by corrosion of ferromagnetic components such as steel bars and steel strands. However,the ferromagnetic materials will be different due to the magnetic time of the site and the geomagnetic field. Also,that will make the magnetic field intensity and the degree of magnetization different in the weak magnetic field detection. Therefore,the purpose is to explore whether the magnetic field and its own magnetization will influence the magnetic flux leakage signals. The contrast experiments of magnetic signal detection were carried out by the magnetic shielding and annealing method to control the two variables,the geomagnetic field and the demagnetizing field. To analyze the experimental results further,COMSOL software is used to simulate the experiment. The experimental results show that the geomagnetic field will not obviously influence the changing the rules of MFL（ magnetic flux leakage） signal. But the self-magnetization is the main factor affecting the MFL. Meanwhile,the simulation results are also consistent with the experimental results.