The Research Of Double-shell Flextensional Transducer

The ever-continuing advance of radiated noise reduction for submarines causes great difficulty in submarine detection by passive sonar, and active sonar had been introduced as important means for detection of distant submarine. Researches about high-power, low-frequency transmitter are the most important technology for long range active sonar systems.Flextensional transducer is a typical low frequency, high-power transmitter. It has the advantage of small volume and lightweight due to displacement amplification .therefore for low frequency, broadband transmission it had been the hot point of corresponding researches all over the world.Methods, which usually be used to achieve broadband transmission, mainly include bandwidth extension of single resonance transducer, multiple mode coupling vibration and combination transducer. In this dissertation researches are focus on low-frequency, broadband flextensional transducer design by means of multiple mode coupling method.Double-shell flextensional transducer means to add another shell at the side of traditional flextensional transducer of class IV.First of all, the structure effect of both shells on resonance frequencies and conductance of the transducer had been studied, which is used to summarized the rules. The double-shell flextensional transducer can be used within frequency range 3~6kHz with peak transmitting voltage response 137dB, fluctuation within the frequency range is less than 7dB .Finally, the transducer was processed by the optimized dimensions and its impedance characteristic and transmitting voltage response were tested. The result shows that the experimental results were well coincide with calculated conclusions getting by software ANSYS.