Modeling and identification of electro-elastic nonlinearities in ultrasonic power transfer systems

We establish a nonlinear non-conservative mathematical framework for the acoustic-electro-elastic dynamics of the response of a piezoelectric disk to high-level acoustic excitation in the context of ultrasound acoustic energy transfer. Nonlinear parameter identification is performed to estimate the parameters representing nonlinear piezoelectric coefficients. The identification is based on exploiting the vibrational response of the disk operating in the thickness mode under dynamic actuation. The nonlinearly coupled electro-elastic governing equations, for the piezoelectric receiver subjected to acoustic excitation, are derived using the generalized Hamilton's principle. The method of multiple scales is used to obtain an approximate solution that forms the basis for parameter identification. The identified coefficients are then experimentally validated. The effects of varying these coefficients on the nonlinear response, optimal resistive elec- trical loading, and power generation characteristics of the receiver are investigated.