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

This paper studies an acoustic source with a relatively small thickness and 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 piezoelectric actuators to convert an in-plane displacement of the actuators to a perpendicular out-of-plane direction. First, an optimization simulation is used to determine the size of the required piezoelectric actuator. Then an equivalent electrical circuit of the lumped acoustic source is developed. This equivalent circuit can directly be connected to the electrical model of a switching amplifier. Finally, a coupled numerical finite element analysis is carried out by using COMSOL Multiphysics software package to model the combination of both flexural mechanism and piezoelectric device. The suggested flexural mechanism is sufficiently narrow to overcome the space limitation challenge in the design.