Finite element investigation of disk transducers from porous piezoceramics of complex structure with cymbal end-caps in external medium

The paper considers two main applications of the transducers in the form of a piezoelectric disk with two metal plate end-caps, which are usually called cymbal transducers. The first variant of the cymbal transducer is an energy harvesting device. Here, the cymbal transducer is located inside the asphalt pavement and generates electric fields under low-frequency oscillatory mechanical action on the pavement. The second version of the transducer is located in a liquid medium and, under the electrical influence oscillating at the first resonant frequency, generates acoustic waves. For both cases, we investigate the efficiency of transducers for four types of piezoceramic materials: solid piezoceramics, conventional porous piezoceramics, and porous piezoceramics with thin and thick layers of metallization of the pore surfaces. The studies were carried out numerically using the finite element method in the ANSYS package. The calculation results showed that the use of porous piezoceramics or porous piezoceramics without or with metallized pore surfaces can increase the efficiency of electromechanical transformations compared to dense ones. Moreover, the fact whether the transducer is excited by the electric potential difference or by the electric current plays a significant role for actuator applications.