巴克豪森效应（MBN）是电磁检测材料微观结构和应力的基本物理效应之一。利用巴克豪森应力检测设备,研究Q235钢在不同深度处的应力分布。定性地分析不同应力下巴克豪森噪声信号幅值变化量与频率的关系,根据集肤效应,不同的脉冲涡流频率对应不同的信号传播深度。定量地研究了2～500 kHz间8个相邻频带在180 MPa应力下巴克豪森噪声信号均方根的变化量,由此分析了不同深度的应力分布情况。

Barkhausen effect is the basic of the detection of micro-structure and stress. The subject focuses on Q235 stress testing by using Barkhausen stress testing equipment. The subject gives a qualitative analysis towards the relation between amplitude variation of the detected MBN signal under different stress relative to the detected MBN signal under 0MPa stress and the different frequencies,and then gives a quantitative analysis to RMS variation of the detected MBN signal under 180MPa stress relative to the detected MBN signal under 0 MPa stress in the eight neighboring pass-bands between 2 kHz and 500kHz. The appropriate digital filter frequency would reflect the distribution of stress.