Analysis of time-frequency representation of Magnetic Barkhausen noise for the need of damage evaluation of steels elements

The application range of Barkhausen noise (BN) technique to nondestructive examination of steel condition or properties is constantly growing. However, the stochastic nature of Barkhausen's noise forces utilization of advanced data processing techniques to extract the knowledge allowing quantitative description of observed signals. Many factors can affect various properties of BN signals derived from time and frequency domain. Therefore, both modes should be considered during feature extraction process. In this paper, in order to combine the information provided in time and frequency regimes, a detailed analysis of time-frequency representation of Barkhausen noise signals allowing quantitative evaluation was carried out. The processing procedures were presented and utilized for estimation of damage progress of stress loaded steel samples. The results were shown and discussed.