Low-frequency sound source with dual bending radiation surfaces

A disk bender sound source with dual radiation surfaces is designed based on the finite element method (FEM) analysis and an equivalent circuit analysis. The results of these analyses results exhibit that the sound source has a low-frequency and high-power radiation capacity and is capable of operating at ten times the normal atmospheric outer water pressure. The sound source comprises of two bending resonators. Each resonator consists of a metal disk and many piezoelectric ceramic segments. Each ceramic segment is firmly bonded to a depression on the metal disk with an epoxy resin adhesive. The sound source has external dimensions of about 80 cm diameter, 9 cm thickness and weighs 130 kg. The resonant frequency obtained is 115 Hz at a depth of 50 m, and the maximum sound pressure level successfully achieved is more than 200 dB re 1 mu Pa at 1 m. For the purpose of using the sound source at great depths, a pressure-compensation method, in which the inner cavity of the sound source is filled with compressed gas, is theoretically investigated.