Prediction of actuating displacement in a piezoelectric composite actuator with a thin sandwiched PZT plate by a finite element simulation

This paper presents the evaluation of a plate-type piezoelectric composite actuator (PCA) with a thin sandwiched plate having four kinds of lay-up configurations by analyzing the flexural displacement For this, a three-dimensional finite element simulation considering the thermal deformation effect of PCA during manufacturing is conducted based on a thermal analogy model. The distribution of residual thermal stresses and the dome height caused by the mismatch in coefficient of thermal expansion (CTE) between the layers of PCA are predicted with the aid of a classical laminated plate theory (CLPT). Results of finite element analyses have revealed that the flexural displacement of PCA subjected to electric fields is considerably affected by the variation of lay-up configuration, the thickness of an embedded PZT wafer and boundary conditions. In particular, as the thickness of the PZT ceramic increases, the bending stiffhess of PCA increases faster than the actuation distance does, which leads to the overall reduction in flexural displacement. It is therefore suggested that the electrically induced flexural displacement of unimorph-type PCA depends more on the bending stiffhess than on the actuation distance.