The radiated sound field of electromagnetic acoustic transducer

The radiated sound field produced within a non-ferromagnetic aluminum by an electromagnetic acoustic transducer that had circle-spiral coil and vertical bias magnetic field was studied.First,the physical and mathematical model was established according to the principle of electromagnetic induction,then the surface force source was decomposed approximately into large horizontal and small vertical components,and the theoretically analytical solution of sound field produced by that force source model was formulated.Finally,the tangential and normal directivity pattern of shear wave and longitudinal wave were calculated numerically and compared with experimental results.The experimental results conform well to the theoretical prediction,which provides theoretical basis for the engineering application of this kind of electromagnetic acoustic transducer.