Characteristics of T(0, 1) Guided-Wave Point-Focusing Electromagnetic Acoustic Transducer for Pipe Inspection

Electromagnetic acoustic transducers (EMATs) are widely used in the field of non-destructive testing (NDT) and non-destructive evaluation (NDE) due to their advantages of non-contact and applicability in complex environments. However, their low energy-conversion efficiency restricts their application in industrial testing. This work proposes a newly designed focusing EMAT based on the T(0, 1)-wave in a pipe to improve the energy conversion efficiency of EMATs. The focal length and defect width are investigated in this paper, and the advantages of the newly designed point-focusing transducer are shown in comparison with traditional unfocused transducers. Results show that the newly designed pipe focusing EMAT can increase the intensity of the defect reflection wave by around 60%, and the reflected wave intensity can be enhanced by 70% in the experiment when compared to the unfocused one.