3-D ultrasonic transducer modeling using the elastodynamic finite integration technique in combination with point-source-synthesis

In the present paper the elastodynamic finite integration technique (EFIT) is combined with point-source-synthesis (PSS) in order to efficiently calculate 3-D ultrasonic wave fields in the time-domain. The technique can be applied to arbitrarily layered locally isotropic media and includes the complete spectrum of linear elastic wave phenomena like surface and interface waves, head waves, mode conversion, and multiple scattering. Various numerical results for the radiation characteristics of circular, rectangular, and ring-shaped piston transducers obtained by the new EFIT-PSS technique are discussed. The results for the circular piston are compared with the corresponding axisymmetric EFIT calculation of the same problem demonstrating the accuracy of the new approach. The proposed technique represents a significant extension of the EFIT framework since it broadens the range of applications to the problem of high-frequency 3-D transducer wave fields that was more or less dominated by semi-analytical methods until now.