Guided wave mode dispersion of transient acoustic emission on copper pipes—Its visualisation and application to source location

CATEGORY: PIPELINES: TRANSIENT ACOUSTIC EMISSION
Guided wave mode dispersion of transient acoustic emission on copper pipes—Its visualisation and application to source location

Type	Journal Article
Author	Chao Wang
Author	Y. H. Joe Au
URL	http://www.sciencedirect.com/science/article/pii/S0888327015004082
Volume	70–71
Pages	881-890
Publication	Mechanical Systems and Signal Processing
Date	March 2016
Abstract	Describes an innovative method for locating a transient acoustic emission (AE) source on a pipeline with two broad-band AE sensors. Using Short Time Fourier Transform (STFT), the method identifies a flexural wave mode, F(1,1), in the two AE signals detected, notes its respective arrival times at different frequencies, and determines the location of the AE source based on the arrival times. Due to velocity dispersion, the arrival time of the wave mode varies with frequency. The method has three main advantages: that the wave speed is not required in the calculation, that it is insensitive to threshold setting for arrival time estimation, and that, at least in theory, the accuracy of the source location can be made as high as desired.