. . . "31028" . . . . . "4"^^ . "I, P(FR-TI3/755)" . "RIV/61388998:_____/14:00438589" . . . "He\u0159m\u00E1nek, Jan" . . . "Multilevel analysis of continuous AE from helicopter gearbox" . "structural health monitoring (SHM); signal processing; acoustic emission (AE); diagnostics of helicopter gearbox; wavelet analysis; continuous acoustic emission"@en . . . "Krofta, Josef" . . "4"^^ . . . "P\u0159evorovsk\u00FD, Zden\u011Bk" . "Multilevel analysis of continuous AE from helicopter gearbox"@en . "[BE9A76D6370D]" . . . . "Multilevel analysis of continuous AE from helicopter gearbox" . . "Acoustic Emission (AE) analyzers for the purpose of structural health or condition monitoring should provide longtime continuous signal records with relatively high sampling frequency. Recorded huge data must be analyzed to disclose any faults in monitored processes or structures like e.g. leakages in pressure vessels or defects in rotating machines and gearboxes, etc. Fast and reliable AE signal processing and analyzing methods are required. In this paper we present such analysis of continuous AE recorded during tests of renovated helicopter gearboxes. Four-channel continuous AE recording system with 4 MHz sampling rate was used in the tests performed under variable 'flight' simulation regimes. As an alternative to classical spectrogram analysis, we proposed to use histograms of time intervals between crossings of threshold amplitudes (multilevel counting) in the wavelet decomposition details. Results obtained on long-time records are discussed."@en . . "Acoustic Emission (AE) analyzers for the purpose of structural health or condition monitoring should provide longtime continuous signal records with relatively high sampling frequency. Recorded huge data must be analyzed to disclose any faults in monitored processes or structures like e.g. leakages in pressure vessels or defects in rotating machines and gearboxes, etc. Fast and reliable AE signal processing and analyzing methods are required. In this paper we present such analysis of continuous AE recorded during tests of renovated helicopter gearboxes. Four-channel continuous AE recording system with 4 MHz sampling rate was used in the tests performed under variable 'flight' simulation regimes. As an alternative to classical spectrogram analysis, we proposed to use histograms of time intervals between crossings of threshold amplitudes (multilevel counting) in the wavelet decomposition details. Results obtained on long-time records are discussed." . "Multilevel analysis of continuous AE from helicopter gearbox"@en . "Chlada, Milan" . . "RIV/61388998:_____/14:00438589!RIV15-MPO-61388998" .