One-dimensional electromechanical equivalent circuit for piezoelectric array elements

In this paper, we report a simple one — dimensional electromechanical method to model piezoelectric transducer array elements well known by slender bar elements. The method is inspired from the Mason's simplified model, which is tested in the case of a piezoelectric plate and extended to a rectangular slender bar. The research work investigates the effects of the material parameters on the electroacoustic performances i.e. on the electrical impedance and the displacement. Firstly, it compares the performances of a piezoelectric plate obtained experimentally and those calculated from the equivalent circuit. Two approaches are tested: the first method consists on the determination of the circuit components from the manufacturer parameters and the second one deduces them from the measured electrical impedance. The second approach is then tested in the case of a piezoelectric rectangular slender bar similar to those constituting the medical transducer arrays. In this case, the electrical impedance and the displacement obtained are very close to the measured ones, especially around the resonance frequency. The same approach will be used to study a complete transducer array i.e. taking into account all the elements, the filling material, the matching layers and the backing. This constitutes the objective of our future works.