THE INCORPORATION OF RIGID COMPOSITES INTO A CONFORMAL HYDROPHONE

Abstract During the past five years, numerous composite configurations have been analysed for hydrostatic transducer application. Although some of these composite configurations have been flexible, a configuration with good sensitivity and mechanical durability has not been produced. The need for a sheet or mat, large area transducer that will conform to the hull of a ship has led to the incorporation of small rigid composite elements into a macrocomposite. The goals set for the conformal transducer were sensitivity greater than -200 dB re 1 V/μPa, operation to at least 7 MPa, maximum frequency of 100 Hz, conforming to a 0·10 m radius and a hydrophone section of at least 0·01 m2. In the study three types of rigid composites are used to determine the effect of compliant hinge material and flexible electrodes on the hydrostatic sensitivity. Typical response of a 1–3 rod composite in flexible form is a sensitivity of -193 dB re 1 V/μPa, with a capacitance of 14 μf per m2 and only 2 dB degradation when operat...