Piezoelectric torsional sensors and actuators - A computational study

This paper concerns a computational study on the realization of piezoelectric torsional actuators and sensors. Exemplarily, a rod with rectangular solid cross-section is considered consisting of a linear elastic substrate material on which orthotropic piezoelectric layers are bonded. On the one hand side, piezoelectric actuation is obtained by applying voltage to the electrodes of the piezoelectric layer. Secondly, the layers can be used as sensors by measuring the voltage on the electrodes which is caused by external torsional loads. Three material types are compared for possible realisations: ammonium dihydrogen phosphate (ADP) and two types of macro fiber composites (MFC). In the framework of Saint Venant's theory of torsion, the actuator and sensor equations are formulated: The actuating torsional moment is proportional to the applied voltage, and the sensor voltage is proportional to the torsional angle. Finally, the results are validated by means of three-dimensional Finite Element computations.