3rd French conference on acoustics
J. Phys. IV France 04 (1994) C5-1193-C5-1196
Traducteurs ultrasonores large-bande à profil vibratoire non uniforme. Théorie et expériencesA. LHÉMERY, D. DE VADDER and S. DIMITRIU
Ecole Centrale Paris, Laboratoire de Mécanique, URA 850 du CNRS, Equipe Ultrasons, Grande Voie des Vignes, 92295 Châtenay-Malabry cedex, France
This paper follows a strictly theoretical one presented in the previous CFA . We had shown the advantage of using nonuniformly excited transducers in wideband pulse-echo method for nondestructive tetsing. We can now produce the source (and sensitivity) profile we want by a masking method not detailed herein. We limit the study to planar disc transducers. The transient field radiated by a planar transducer vibrating with a conventional uniform profile is often described as a superposition of a plane wave and edge (diffracted) waves. We consider three different profiles : uniform profile, profile favoring the plane wave component and another favoring the edge wave. We first compare theoretical with measured echo-responses from simple-shaped targets proving the validity of the masking technique. Then, practical transducers are studied in terms of their axial or radial resolution and sensitivity.
© EDP Sciences 1994