Guided Wave Inspection of Pipes Using Electromagnetic Acoustic Transducers

This research covers modeling of Electro Magnetic Acoustic Transducers (EMATs) and their application in excitation and detection of longitudinal guided Lamb wave modes for evaluation of flaws in cylindrical pipes. The combination of the configuration of transducers and the frequency of the input current is essential for successful excitation of desired guided wave modes and for proper interpretation of the results. In this study EMATs were successfully constructed and longitudinal modes L(0,1) and L(0,2) were excited in the pipe. From the recorded signals the level of simulated damage in pipes could be assessed. It is also possible to theoretically predict the location of the pipe flaws. Theoretical predictions are matched with experimental results. Dents and holes in pipes are detected by appropriate signal processing of received L(0,1) and L(0,2) modes