Model for a piezoelectric polymer flexural plate hydrophone

A mathematical model of the piezoelectric polymer flexural plate hydrophone is presented, with application to sheets of polymer attached to air-backed rectangular flexural plates. Expressions are given for the low-frequency electroacoustic sensitivity, as well as for the evaluation of hydrophone mechanical behavior under hydrostatic loading. Numerical results are presented for the supported plate and for the special case of a supported beam. The analytic results reveal that the selection criterion for the substrate plate should be its strength-to-elastic modulus ratio, in order to maximize the product of hydrophone sensitivity and maximum operating pressure. The theoretical model is applied to a plastic flexural plate polymer hydrophone, which results in close agreement between the predicted and measured sensitivities.