PSI - Issue 28

I. Shardakov et al. / Procedia Structural Integrity 28 (2020) 1795–1801 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 4. Vibration response of the pipeline caused by shutoff valves

Figures 5a and 5b show the frequency characteristics of sound vibrations of a microphone caused by a stationary gas outflow for 3.3 seconds after opening a hole with a diameter of 50 mm. As can be seen from the figure, the main audio signal is in the frequency range of 5-7 kHz, however, the spectrum also contains frequencies below 1.5 kHz, which can be recorded by an accelerometer.

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Fig. 5. Fourier (a) and Wavelet (b) spectrum of the sound signal in the frequency range of 50 Hz–10 kHz and wavelet spectrum of the sensor S3 signal (c)