基于MBN法的应力检测参数优化及试验

Optimization and Experimental Study of Stress Detection Parameters Based on MBN Method

搭建了基于磁巴克豪森噪声(MBN)原理的电磁检测平台,以Q235钢为试验对象开展了应力检测研究。在试验之前采用不同的波形、频率和电压进行测试,分析MBN信号峰值与频率、电压的关系,确定最优的激励参数。通过静载拉伸试验确定MBN信号与拉应力之间的关系,拟合MBN信号峰值与拉应力的关系曲线,分析信号峰值作为应力评价指标的可行性。结果表明:正弦波作为激励信号产生的MBN信号特征明显、信噪比高;MBN信号峰值随拉应力的增大而先增大后减小;分析非线性拟合曲线可以对应力集中程度进行评估。

In this paper,the electromagnetic detection platform based on magnetic Barkhausen noise（MBN）principle is built,and the stress detection is carried out with Q235 steel as the experimental object.Before and after the test,different waveforms,frequencies and voltages were used to test the relationship between the peak value of MBN signal and frequency and voltage,and determine the optimal excitation parameters.The relationship between the MBN signal and the tensile stress is determined by the static load tensile test.The relationship between the peak value of the MBN signals and the tensile stress is fitted and the feasibility of using the peak value of the signal as the stress evaluation index is analyzed.The results show that the MBN signal generated by the sine wave as the excitation signal has obvious characteristics and the SNR is high;the peak value of the MBN signal increases first and then decreases with increasing tensile stress;the nonlinear fitting curve can be used to evaluate the stress concentration.