The influence of temperature and bonding thickness on the actuation of a cantilever beam by PZT patches

Abstract

The goal of this work is to investigate the sensitivity of transfer of piezoelectric actuation efficiency to a cantilever beam due to variations in the environmental temperature and possible variations in the thickness of the adhesive layers bonding actuators to a beam. Investigations are first done analytically on the basis of a static linear longitudinal strain distribution along the whole beam/bonding/actuators section, as well as the shear lag model. In addition to the known conditions for transfer of actuation efficiency such as impedance matching, one obtains further requirements for a transfer of this actuation efficiency, of which the most important is a small thickness of the adhesive layer. However, the influences of temperature and of bonding thickness are smaller than expected; that is, variations induced by practical mounting and by use outside the laboratory have no pronounced effect on the transfer of the actuation efficiency. Using then the finite element program ANSYS, the complete system was modelled, including the adhesive layers. For the FEM calculations, the temperature dependences of all material properties were linearized. Results show that the eigenfrequencies of the beam vibration decrease only slightly at higher temperature and for thicker adhesive layers, without any reduction in the resonance amplitude. The findings are partly validated by experimental measurements.