交变磁场测量系统数值仿真分析

利用有限元分析软件，建立了交变磁场测量系统的数值仿真模型。基于这个模型，分析了检测位置对确定缺陷大小和分布的影响，发现检测路径离裂纹中心越近，检测到的磁场分布信号越好；检测平面与工件表面间隔越小，Bz曲线越准确，但过小的间隔却可能增大Bz曲线的噪声。同时研究了缺陷几何尺寸与表面磁场分布的对应关系，进一步验证了表面磁场曲线极值间隔与缺陷长度的对应关系；以及在确定缺陷长度的基础上，缺陷深度与Bz曲线极小值之间的一一对应。以上结论为识别缺陷特征专家系统的实现提供了理论依据．

NumericalL Simulation Analysis Based on the AlternafingG Current Field Measurement System

In this paper, a numerical simulation FEA model is built up based on the conventional current injection method, The crack signal, which is the variation of the inspecting position and the size of the crack, is investigated by varying the distance between the inspecting path and the center of the crack, the crack length and depth. It is shown that the shorter distance brings out the better crack signal and too short distance will cause great noise to the sample signals of. Bx The corresponding relation between the size of the slot and the distributing of Bx and Bz is also validated by this model. All the results can be used as the academic base to realize the expert system of the sizing of slots.