Influence of Air Pressure on the Amplitude of Sound Frequency Spectra when Simulating a Crack in a Pipeline

This paper intends to determine the influence that the amount of air pressure in a pipeline has on the amplitudes of the sound frequency spectra that occur when a pipeline cracks. In order to simulate the cracking of the pipe, in the experimental tests, a route was constructed with a pipe through which pressurized air flows and which has a removable section where portions of the pipe with holes of different diameters can be added. The hole represents the crack. Frequency spectrum measurements were made for FFT (Fast Fourier Transform), CPB (Constant Percentage Bandwith) and Overall spectral analysis. The Bruel & Kjær spectral acquisition and analysis system was used for the measurements, consisting of a signal analyzer, a microphone and a laptop with PulseLabshop software installed for processing the acquired signals.The obtained data can be a starting point for the design of a pipes crack detection/location system based on the spectral analysis of sound vibrations. (author).