Computer simulation of torsional transducer from porous piezoceramics with twisted rod

This paper considers a piezoelectric transducer operating on torsional modes. The transducer consists of a piezoelectric cylinder rigidly coupled with an elastic twisted rod. Along the central axis in the cylinder and in the rod, there are the cylindrical hollows with the same radius. The piezoelectric cylinder is made of PZT ceramics, polarized in the circumferential direction. It has two electrodes at the end surfaces and it is rigidly fixed at the bottom end. When a harmonically varying voltage or electric current is applied to the electrodes, in the cylinder predominantly torsional oscillations are generated. The naturally twisted shape of the elastic rod promotes to an additional amplification of torsional vibrations. The analysis of the piezoelectric transducer was carried out in the ANSYS finite element package. A comparison was made of the amplitude-frequency characteristics of the transducer near the first modes of thickness oscillations for the cases of dense and porous PZT ceramics, for the cases of twisted and non-twisted forms of an elastic rod, and for the cases when the oscillations are excited by voltage or by current generators. The results of computational experiments have shown the highest efficiency of the transducer from porous piezoceramics with a twisted rod when the vibrations are excited by the electric current generator.