Effect of Different Line Angle of Meander Coil on EMAT Energy Transfer Efficiency

By studying the energy transfer efficiency of the meande coil electromagnetic ultrasonic transducer, the impact of meande coils with different line angles on the energy transfer efficiency of the EMAT was analyzed. According to the principle of acoustic beam pointing in the direction and by changing the angle of the current-carrying conductor, 0 degrees, 30 degrees, 60 degrees, and 90 degrees meander coils were designed for the excitation of ultrasonic guided wave, and the transceiver separation transducer structure on the steel plate was adopted for experimental research. The results have shown that when the current-carrying conductor angle of the meander coil is 0 degree, the excitation acoustic energy of EMAT is focused, owing high directivity and strong echo signal amplitude, which provides the possibility for the long distance detection in the steel plate; when the current-carrying conductor angle of meander coil increased to 30 degrees, 60 degrees and 90 degrees, the EMAT inspires pure acoustic signal of being easy to identify and simplify the modal analysis, which has great significance for the signal processing in steel plate detection of the engineering.