Numerical modeling of a flexural displacement-converter mechanism to excite a flat acoustic source driven by piezoelectric stack actuators

Abstract

This paper studies an acoustic source with a relatively small thickness and a high bending stiffness. The acoustic source operates in the low frequency, quasi-static regime. The focus of the current study is on the actuation part in order to design an appropriate excitation mechanism. A flexural mechanism is modeled in combination with a piezoelectric actuator to convert an in-plane displacement of the actuator to the out-of-plane direction. First, an optimization simulation is used to determine the size of the required piezoelectric actuator. An equivalent electrical circuit of the lumped acoustic source is used for the optimization. A coupled 3D numerical finite element (FE) analysis is carried out using COMSOL Multiphysics software package. The fully-coupled analysis combines the suggested flexural mechanism, the piezoelectric stack actuator, and the thin acoustic source. Finally, the sound pressure field that is generated by the thin acoustic source is investigated and compared using both the finite element analysis and the lumped model.