Analysis of partially electroded piezoelectric actuators with nonuniform thickness for the purpose of reducing actuating shear stress concentration by ansys

An elastic plate with thin piezoelectric films bonded on its two major surfaces is a typical smart structure which is used in actuation and sensing. The useful deformation of the smart structure is caused by the shear stress transferring from the actuators to the elastic plate. This shear stress is concentrated at two ends of the interface between the actuator and the plate. This concentration may induce undesirable delamination of the actuator from the plate. It was theoretically proved that actuators with partially covered electrodes have a much less concentrated actuating shear stress than that with fully ones. An actuator with nonuniform thickness was also found that may reduce the concentration of shear stress. The previous theoretical results were based on two simplified models. However, it is very difficult to get an analytical solution when the actuator owns the two characteristics at the same time, i.e. not only with partially covered electrodes, but also with an in-plane varied thickness. In this paper, we turn to use ANSYS to obtain useful numerical results from cases which are nearly impossible to be solved analytically. We study the effect of the electroded area of the actuator on reducing the concentrated shear stress. Moreover, we investigate the shear stress distribution under different variation of the actuator thickness. An optimal thickness profile is obtained. This work is considered as a frontier of smart structure.