Influence of measurement conditions on the Magnetic Barkhausen Noise properties

Use of Time-Dependent Multispectral Representation of Magnetic Barkhausen Noise Signals for the Needs of Non-Destructive Evaluation of Steel Materials

“…At the same time, the concentration of the domain reorientation phenomenon at a shorter time along with increase of eddy current damping has an impact at higher bands. Thus, the highest sensitivity of features to materials changes can be obtained for middle bands of the frequency range [25]. Therefore, during the tests, the excitation coil of the BN transducer was driven with a sinusoidal waveform with a frequency f E of 10, 20 and 30 Hz.…”

“…Consequently, these obstacles arising in the material require additional energy and cause discontinuous changes of the magnetic state. This phenomenon has been studied and gradually used for non-destructive testing (NDT) of materials [4,5,6,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33]. The stepwise change of the magnetization level during operation of the alternating magnetizing field can be observed by coil placed in the neighbourhood of the material.…”

“…Furthermore, in order to extend the range of features being extracted, frequently the envelope of BN signal is also used. Thus, the shape of the envelope can be additionally studied to complement the information by the analysis of features such as peak height, peak position, full-width-at-half module, skewness or kurtosis [11,12,19,24,25]. As the dynamics of BN signal can also vary, the F domain has been also used.…”

“…The signal representation in T as well as in F domain changes simultaneously. Moreover, the dynamics of the phenomenon depends on many factors, including the stress state of the structure [7,13,19,20,25,29,33]. In such cases, the traditional methods of frequency analysis are not adequate while they generalize the dynamics of non-stationary signal over whole considered period of time.…”

Analysis of measurement conditions influence on the magnetic Barkhausen noise phenomenon

“…Most often, for the purposes of quantitative description of observed Barkhausen noise clusters, an analysis of its properties in the time domain and in the frequency domain is performed. The work [10] presents the results of studies on the impact of measurement conditions on MBN signals expressed in time or frequency domain. However, due to the stochastic nature of the measured MBN signals, analysis procedures have been developed using the combined representation of time and frequency, which allows obtaining holistic information about changes in the material [15÷18].…”