The Study Of Giant Magnetostrictive Tonpilz Transducer

With the progress of modern sonar technologies and ocean technologies, it is more and more important to improve the performance of underwateracoustic transducers and arrays. Thus, the broad bandwidth, high power and small dimension transducer become the primary candidate and also become the primary aspect of research by transducer investigators. A giant magnetostrictive Tonpilz transducer is designed in order to develop a transducer with those qualities in this thesis.According to theory about piezoelectric of finite-element method, the relationship between piezoelectric analysis and magnetoelectric analysis is figured which can apply for the magnetostrictive transducer. The magnetic circuit optimization work is carried out for rare-earth transducer using giant magnetostrictive material. The relationship between the distribution of magnetic induction intensity, which acts as the major parameter to describe the efficiency of the use of magnetic energy, and the structure of magnetic circuit is studied and one kind of advanced magnetic circuit configuration is proposed. Then, the broad bandwidth is achieved by coupling between longitudinal vibrating mode of transducer and flexural vibrating mode of head in the coupling-field analysis of FEM. At last, the transmit current resonance, resistance and beam patterns of transducer are achieved by ANSYS.Then the prototype of the giant magnetostrictive Tonpilz transducer is fabricated according to the conclusions of optimization analysis. The in-water measured results indicate a mechanical Q of 1.6, a maximum Source Level of 201dB re 1uPa/m at 1 Amps AC drive and bandwidth of 6.2kHz to 11.8kHz±1.5dB.