磁巴克豪森噪声检测材料疲劳的励磁频率优化研究

Excitation frequency optimization for material fatigue inspection based on magnetic Barkhausen noise

磁巴克豪森噪声在铁磁性材料早期疲劳损伤的检测中具有巨大的应用潜力。在疲劳检测过程中,励磁频率作为磁巴克豪森噪声的激发源,对检测结果有重要影响。实验研究励磁频率对磁巴克豪森噪声检测铁磁性材料疲劳时检测结果的影响规律,以20R钢材料为对象进行低周疲劳实验,并在励磁频率分别为9,16,35,60 Hz下对取自同一母材的3个试件进行疲劳过程中的磁巴克豪森噪声信号测量。实验结果表明,励磁频率较小时,3个试件测量结果分散,而当选择60 Hz励磁频率时,3个试件测量结果一致性良好;同时在60 Hz较高励磁频率下,疲劳过程中磁巴克豪森噪声信号幅值平均变化量是9 Hz较低励磁频率时的2.2倍。60 Hz较高励磁频率对材料的疲劳损伤程度的分辨力强,且分散度小。

Magnetic Barkhausen noise has great potential in early fatigue detection of ferromagnetic materials.In the process of fatigue detection,the excitation frequency,as the excitation source of magnetic Barkhausen noise,has an important influence on the detection results.The influence of excitation frequency on the fatigue detection results of ferromagnetic materials by magnetic Barkhausen noise was experimentally studied.The low-cycle fatigue experiment was carried out with 20 R steel as the object,and the magnetic Barkhausen noise signal was measured in the fatigue process of three specimens from the same base material under the excitation frequency of 9,16,35,60 Hz respectively.The experimental results show that when the excitation frequency is small,the measurement results of the three specimens are scattered.When the excitation frequency of 60 Hz is selected,the measurement results of the three specimens are in good consistency.At the same time,at a high excitation frequency of 60 Hz,the average amplitude variation of magnetic Barkhausen noise signal during fatigue is 2.2 times that at a low excitation frequency of 9 Hz.The high excitation frequency of 60 Hz has a strong resolution to the fatigue damage degree of the material,and the dispersion degree is small.