Influence of defect in an excited steel plate on the results of time-frequency analysis

Abstract

The paper pertains the use of non-invasive diagnostic methods to assess the condition of metal elements of machinery and equipment or metal components of building structures. The conducted research concerns the analysis of acoustic signals generated during the excitation of a steel plate and the influence of discontinuities such as grooves and apertures in its structure on spectrogram of recorded acoustic emission signals. Since the presence of the opening causes a significant increase in the initial phase of the acoustic event, higher frequencies (20-55 kHz) and faster decay of the signal, so it should be noted that the frequency analysis of recorded signals, in the initial phase of the acoustic event, can be considered as an indicator of the damage presence.