Acoustic Emission Source Location in Steel Structures Using a Wavelet Transform Analysis and Modal Location Theory

Source location is an important feature of acoustic emission (AE) damage monitoring in steel structures. The ability to accurately locate sources can assist in source characterisation and early warning of failure. This paper describe the development of a novel AE source location technique termed “ Wavelet Transform analysis and Modal Location (WTML)” based on Lamb wave theory and time-frequency analysis that can be used for global monitoring of plate like steel structures. Source location was performed on a steel plate of 790 x 300 mm with nominal thickness of 5 mm under a planar location test setup using H-N sources. The accuracy of the new technique was compared with other AE source location methods such as the time of arrival (TOA) technique, triple point filtering and DeltaT location. The results of the study show that the WTML method produces more accurate location results compared with TOA and triple point filtering location methods. The accuracy of the WTML approach is comparable with the deltaT location method but requires no initial acoustic calibration of the structure.