旋转弯曲疲劳件的法向磁信号分布

为对旋转弯曲疲劳过程中的磁记忆信号进行分析，从磁记忆的物理基础出发，把旋转弯曲疲劳试验件看成一个磁体，试件的疲劳破坏过程就是试件由一个磁体变成两个磁体的过程。指出在试件表面检测到的磁场是环境磁场、试件的磁感应磁场和漏磁场的叠加，并分析了沿试件轴向的法向磁信号的分布变化。最后通过旋转弯曲疲劳试验，验证了理论分析结果。理论分析和试验结果均显示，疲劳破坏前法向磁信号出现显著的异常特征，可用其进行疲劳损伤诊断。

Normal Magnetic Signals Distribution Analysis of Rotating Bending Fatigue Specimen

In order to study the normal magnetic memory signals in the process of rotating bending fatigue, the rotating bending fatigue specimen was treated as a magnet based on magnetic memory＇s physical basis. The fatigue failure process of specimen was a process that one magnet became two. It was pointed out that the magnetic field measured on the specimen surface included environment magnetic field, magnetic induction magnetic field and leakage magnetic field. The distribution variation of normal magnetic signals was analyzed, and the results were validated by rotating bending fatigue experiments. Theoretical analysis and experimental results both indicated that normal magnetic memory signals had remarkable anomaly characteristics before failure, which could be used for fatigue damage diagnoses.