Reduction of applied electric potential controlling thermoelastic displacement in a piezoelectric actuator

Abstract

The present paper discusses how to reduce the applied electric potential which controls a distribution of the elastic displacement, when temperature change induces elastic deformation in a piezoelectric-based solid state actuator. The actuator consists of an isotropic structural plate, onto which multiple piezoelectric ceramic plates of crystal class 6mm are perfectly bonded. The analysis of this thermoelastic problem leads to electric potential applied to piezoelectric ceramic plates. Numerical calculations are carried out for an isotropic steel plate, onto which multiple cadmium-selenide plates are perfectly bonded. Finally, it is shown that the maximum applied electric potential in the case of ten cadmium selenide plates can be reduced to 11% of that derived from the previous study of a similar problem of one cadmium selenide plate bonded onto an isotropic steel plate. IntroductionDisplacement-control unit accurate to submicron is required in the areas of optics, astronomy and super precision machining. In controlling such a microscopic displacement, elastic deformation in the actuator induced by change of the temperature should be estimated, because it is very dif®cult to strictly maintain the thermal conditions of the surrounding medium. Now, piezoelectric materials possess a coupling effect between elastic and electric ®elds. Recent interest in the use of such piezoelectric materials as sensors and/or actuators operating in thermal environments is evidenced by some publications [1±12].The concept of utilizing a piezoelectric ceramic plate as an actuator controlling thermoelastic displacement was examined in [7±9]. The actuator was constructed of an isotropic structural plate, onto which a piezoelectric ceramic plate of crystal class 6mm was perfectly bonded. When heating temperature acted on the bottom surface, and then the combined plate was deformed, the applied electric potential on the top surface was derived which gave the prescribed distribution of normal elastic displacement on the bottom surface. It was shown numerically that the applied electric potential was very high. This presents a serious problem for practical applications of this actuator, and it must be solved. A solution to the problem is to lay other piezoelectric ceramic plates on the top of the combined plate.In order to reduce the applied electric potential, the present paper deals with displacement control of an isotropic structural plate onto which multiple piezoelectric ceramic plates of crystal class 6mm are perfectly bonded. This thermoelastic problem is analyzed by means of the potential function method, and the applied electric potential is derived. Numerical results are obtained for the temperatures, stresses and applied electric potential in an isotropic steel plate, onto which multiple cadmium selenide plates of crystal class 6mm are perfectly bonded. The effects of the number and thicknesses of the cadmium-selenide plates on the stresses and applied electric potential are investigated. As compared with the numerical results, ...

Optimum Design of a Multilayered Composite Plate Using Neural Networks

“…The temperature changes that satisfy the boundary conditions (1)-(3) were obtained in the previous study [6].…”

“…In order to reduce the applied electric potential, a composite plate with multiple piezoceramic layers was studied by Ashida [6]. It is seen from the numerical results that as the number of piezoceramic layers increases, the maximum applied electric potential certainly decreases, but the shear stress becomes larger because each piezoceramic layer gets inevitably thinner.…”

“…The objective of this study is to determine the thickness of each piezoceramic layer in order to minimize the maximum value of the applied electric potential distributions, when the maximum tensile, compressive, and shear stresses induced in the piezoceramic layers are subject to constraints. Based on the analytical results obtained in the previous study [6], the thickness of each piezoceramic layer is determined by the approximate optimum design using hierarchical neural networks. Finally, numerical results for the optimum design of the composite plate are shown in figures and tables.…”

Functionally graded piezoelectric cantilever beam under load

“…It is well known that piezoelectric materials have been widely used as sensors and actuators in control systems [11,12]. Traditional sensors and actuators are often made of the uni-morph, the bi-morph and the multimorph materials.…”

Control of transient thermoelastic displacement of a two-layered composite plate constructed of isotropic elastic and piezoelectric layers due to nonuniform heating

“…The piezothermoelastic problem concerning control of thermally induced elastic displacements of an isotropic plate with a piezoelectric plate of crystal class 6mm was investigated in [2±4]. In order to reduce the applied electric potential, the same piezothermoelastic problem concerning multiple piezoelectric plates of crystal class 6mm was investigated in [5]. The shape control of a cylindrical panel or a rectangular hybrid plate with some piezoelectric layers under thermomechanical load were reported in [6,7], however, these papers are restricted to three-dimensional steady state piezothermoelastic problems.…”