The most important property of a piezoelectric material for practical applications is its ability to convert electrical energy into mechanical energy and vice versa. As it is well known, the electromechanical coupling factor κ fully characterize this energy conversion. In a previous work we demonstrated that, like in static conditions, it is possible to define the κ factor also in dynamic situations as a ratio of energies. We also showed that the value of the κ factor computed in this way (κω) coincides with the one obtained by using the empirical relation of the effective coupling factor κeff. In this work we show that the proposed definition of the κ factor as ratio of energies can be extended to lossy elements, but, in this case, the keff does not give accurate estimation of the coupling factor. For composite Langevin-type structures, both κ, and κeff-fails
The Evaluation of the k Factor for Lossy and Composite (Langevin–Type) Piezoelectric Elements
IULA, Antonio;
1999-01-01
Abstract
The most important property of a piezoelectric material for practical applications is its ability to convert electrical energy into mechanical energy and vice versa. As it is well known, the electromechanical coupling factor κ fully characterize this energy conversion. In a previous work we demonstrated that, like in static conditions, it is possible to define the κ factor also in dynamic situations as a ratio of energies. We also showed that the value of the κ factor computed in this way (κω) coincides with the one obtained by using the empirical relation of the effective coupling factor κeff. In this work we show that the proposed definition of the κ factor as ratio of energies can be extended to lossy elements, but, in this case, the keff does not give accurate estimation of the coupling factor. For composite Langevin-type structures, both κ, and κeff-failsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
