Nonlinear bending characteristics and sound pressure level of functionally graded piezoelectric actuators under AC electric fields: simulation and experiment

This paper describes the results of our numerical and experimental studies of the nonlinear electromechanical response in functionally graded piezoelectric actuators under alternating current (AC) electric fields. A nonlinear finite-element method is employed to simulate the dynamic bending of clamped-clamped functionally graded piezoelectric bimorphs. A phenomenological model of domain wall motion is used in the computation, and the effects of AC electric field amplitude and frequency, number of layers and property gradation on the sound pressure level, deflection and internal stresses of the actuators are examined. The sound pressure level is also measured to validate the numerical predictions, and comparison is made between numerical results and experimental data.