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Properties of Amplitude Distributions of Acoustic Emission Signals Generated in Pressure Vessel During Testing

Witos Franciszek

Archives of Acoustics

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2019

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Vol. 44, No. 3

493--503

EN

In the paper, the results of investigations on the properties of acoustic emission signals generated in a tested pressure vessel are presented. The investigations were performed by repeating several Times the following procedure: an increase in pressure, maintaining a given pressure level, a further increase in pressure, and then maintaining the pressure at new determined level. During the tests the acoustic emission signals were recorded by the measuring system 8AE-PD with piezoelectric sensors D9241A. The used eight-channel measuring system 8AE-PD enables the monitoring, recording and then basic and advanced analysis of signals. The results of basic analysis carried out in domain of time and the results of advanced analysis carried out in the discrimination threshold domain of the recorded acoustic emission signals are presented in the paper. In the framework of the advanced analysis, results are described by the defined by the author descriptors with acronyms ADC, ADP and ADNC. Such description is based on identifying the properties of amplitude distributions of acoustic emission signals by assigning them the level of advancement. It is shown that for signals including continoues AE or single burst AE signals descriptions of such registered signals by means of ADC, ADP and ADNC descriptors and by Upp and Urms descriptors provide identical ordering of registered acoustic emission signals. For complex signals, the description using ADC, ADP and ADNC descriptors based on the analysis of amplitude distributions of recorded signals gives the order of signals with more accurate connection with deformational processes being sources of acoustic emission signals.

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Partial Discharges Within the Bars Assigned for Generators Coils

Witos F.

Molecular and Quantum Acoustics

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2005

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Vol. 26

283-298

EN

The paper contains the analysis of PD investigations results (within the bars assigned for generators coils) obtained parallel on the ground of the electric method and acoustic emission method as well as unified eclectro-acoustic method. The analysis of results obtained by means of electric method characterizes kind and parameters of PDs. The analysis of results obtained by means of acoustic emission method contains acoustic description of AE signal and detailed analysis of amplitude distributions shapes which gives deformation processes description and PD sources location. Detailed analysis of amplitude distributions shapes has been carried out by means of two methods resultant from definition of AE descriptors and application of Kohonen neural network. The unified eclectro-acoustic method consists in parallel utilisation both methods to mutual verify obtained results.

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Investigation of Partial Discharge Within Generator Coil Bars on the Ground of Acoustic Emission Method

Witos F.

Molecular and Quantum Acoustics

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2002

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Vol. 23

433-442

EN

Investigations of partial discharges withis bars of generator coils have been made by means of acoustic emission method. Two ways of analysis of shapes of obrained AE amplitude distributtions are presented. The first cosists in definition and calculations of advanced AE desriptions, whichn can distinguish deformation process. The second way is based on Kohonen neuron network, used to distinguish and classify of images. The result of both mathod of analysis are compared with the measuremants of the apparent charge which have been curried out simultaneously to EA investigations.