大面积钢板局部磁化的三维有限元分析

采用三维有限元方法研究了大面积钢板漏磁检测的局部磁化，分析了钢板宽度变化对磁化效果的影响，论证了局部磁化的可行性．研究了励磁装置中永磁体磁厚度、磁极面积以及磁化间隙等变化对局部磁化效果的影响．分析表明，永磁体极面积是影响磁化性能的关键因素，当钢板内局部被磁化饱和时，永磁体厚度和磁化间隙的影响不显著．根据有限元优化结果设计的大面积钢板漏磁检测的励磁装置在实践中得到了应用．

3D FEM of local magnetization for steel plate with large area

The local magnetization of steel plate with large area was studied by using 3D finite element technology. The influence of steel plate width on local magnetization of steel plate was studied. Results showed that the local region of steel plate between the magnet poles can be magnetized to saturation even if the specimen width was infinite. The method for local magnetization was proved to be feasible. The influences on the local magnetization of steel plate by permanent magnet thickness, magnet pole area and the distance from pole to plate surface were studied. The magnet pole area was the key parameter for local magnetization. The effects of magnet thickness and the distance from pole to plate surface were not distinct when the local region was magnetized to saturation. A magnetizing system was designed according to the optimized results, and used in practice for testing the magnetic flux leakage in large area plate.