Influences of dome height and stored elastic energy on the actuating performance of a plate-type piezoelectric composite actuator

The objective of this study is to examine the influences of dome height and stored elastic energy induced by thermal deformation after a curing process on the actuating performance of plate-type piezoelectric composite actuators (PCAs). The PCA is made of woven fabric fiber skin layers and a PZT ceramic core layer. The actuating performance has been evaluated in terms of flexural displacement with and without a load of mass at simply supported and fixed-free boundary conditions. Additionally, the stored elastic energy of the PCA is obtained via a flexural mechanical bending test. The results indicate that in a static state with increasing electric field, PCA- I with a top layer of three carbon-epoxy plies exhibits better performance than PCA-2 with a top layer of two carbon-epoxy plies and one glass-epoxy ply and PCA-3 with a top layer of one carbon-epoxy ply and two glass-epoxy plies in terms of free displacement as well as load capability due to its increased dome height and stored elastic energy. The behavior of the flexural free displacement of the PCA in a quasi-static state at a drive frequency of 1 Hz shows non-linearity at the simply supported boundary condition, whereas the flexural displacement increases in a nearly linear manner in a fixed-free condition. In a dynamic state above I Hz, the magnitude of free displacement for each PCA reaches a peak value at the specific frequency, i.e. the resonance frequency. The corresponding resonance frequency varies among the PCAs due to differences in bending stiffness. Furthermore, as the applied electric field is increased, each PCA displays a slight decrease in resonance frequency because of a PZT ceramic softening effect. On the basis of experimental results, it has been concluded that the flexural displacement of the asymmetrically laminated PCA presented here can be controlled such that applications for pumping devices will be possible subsequent to investigation of the drive frequency along with the applied electric field. (C) 2007 Elsevier B.V. All rights reserved.