Low-Profile, Broadband, Shear-Mode SONAR Transducer for Deep Submergence Applications

The main objective is to design, build and test a low-profile, high-power, low-frequency broadband, d36 shear-mode piezoelectric single crystal transducer capable of operating at submarine depths. Because of Phase I program constraints, we designed an initial modified shear mode transducer with a nylon cylinder head-suspension, that would be used in a d36 design capable of operating at submarine depths. This transducer was FEA modeled, fabricated and tested with PZT-5A d15 shear mode elements of the same size as the legacy single crystal d36 elements. A wide band response from below 2 kHz to over 9 kHz was measured and FEA results showed no significant stress in the single crystal material for a hydrostatic pressure of 1,000 psi. During the proposed Phase II a partial array of improved pressure tolerant d36 shear mode transducers will be developed. To this end, and before the array development, an optimized, improved, pressure-tolerant d36 single crystal version would be FEA modeled, fabricated and tested in-air and in-water under low and high pressures.