• Smart Structures and Systems
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• v.5 no.5
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• pp.547-564
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• 2009

Based on the theory of piezoelasticity, an analytical solution for a typical multilayer piezoelectric composite cantilever is obtained by the Airy function method. The piezoelectric cantilever may consist of any number of layers. Moreover, the material and thickness for different layers may be different. The solution obtained in the present paper is concise and can be easily applied for the bending analysis of multilayer piezoelectric actuators considering the effect of bonding layers and electrodes. At last, a comprehensive parametric study is conducted to show the influence of electromechanical coupling (EMC), the number of piezoelectric layers, the elastic modulus of elastic layer and the thickness ratio on the bending behavior of actuators. Some interesting results for the design of multilayer piezoelectric actuators are presented.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.680-683
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• 2001

The output characteristics of step-down piezoelectric transformer is changed by a structure of layers. In this paper, we simulated output characteristics of multi-layer piezoelectric transformers with variation of output layers. Also, fabricated piezoelectric transformers were compared with simulated data. From simulated piezoelectric transformers, the output voltage decreased with increasing number of layers. From these results, piezoelectric transformers were made and the output electrical power of the transformers was measured at resonance frequency and at other frequency. The electrical power of transformers was measured on each transformer's resonance mode. However, measured value of 12-layed transformer's output power was smaller than that of 6-layered transformer's one. It is supposed that internal capacitance and reactance of the piezoelectric transformer's were effected in this result. Therefore we need to connect other road resistance and capacitance in output circuit, in order to increase electrical power of transformers.

• Structural Engineering and Mechanics
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• v.62 no.6
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• pp.675-693
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• 2017

In this paper, based on the first-order shear deformation plate theory, buckling analysis of piezoelectric coupled transversely isotropic rectangular plates is investigated. By assuming the transverse distribution of electric potential to be a combination of a parabolic and a linear function of thickness coordinate, the equilibrium equations for buckling analysis of plate with surface bonded piezoelectric layers are established. The Maxwell's equation and all boundary conditions including the conditions on the top and bottom surfaces of the plate for closed and open circuited are satisfied. The analytical solution is obtained for Levy type of boundary conditions. The accurate buckling load of laminated plate is presented for both open and closed circuit conditions. From the numerical results it is found that, the critical buckling load for open circuit is more than that of closed circuit in all boundary and loading conditions. Furthermore, the critical buckling loads and the buckling mode number increase by increasing the thickness of piezoelectric layers for both open and closed circuit conditions.

• Structural Engineering and Mechanics
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• v.67 no.1
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• pp.33-43
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• 2018

The dynamic output-feedback robust control method based on linear matrix inequality (LMI) method is presented for suppressing vibration response of a functionally graded material (FGM) beam with piezoelectric actuator/sensor layers in this paper. Based on the reduced model obtained by using direct mode truncation, the linear fractional state space representation of a piezoelectric FGM beam with material properties varying through the thickness is developed by considering both the inherent uncertainties in constitution material properties as well as material distribution and the model error due to mode truncation. The dynamic output-feedback robust H-infinity control law is implemented to suppress the vibration response of the piezoelectric FGM beam and the LMI method is utilized to convert control problem into convex optimization problem for efficient computation. In numerical studies, the flexural vibration control of a cantilever piezoelectric FGM beam is considered to investigate the accuracy and efficiency of the proposed control method. Compared with the efficient linear quadratic regulator (LQR) widely employed in literatures, the proposed robust control method requires less control voltage applied to the piezoelectric actuator in the case of same control performance for the controlled closed-loop system.

• Transactions on Electrical and Electronic Materials
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• v.18 no.4
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• pp.181-184
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• 2017

Multilayer ceramics in which piezoelectric layers of $0.90Pb(Zr_{0.48}Ti_{0.52})O_3-0.05Pb(Mn_{1/3}Sb_{2/3})O_3-0.05Pb(Zn_{1/3}Nb_{2/3})O_3$ (0.90PZT-0.05PMS-0.05PZN) stack alternately with silver electrode layers were prepared by an advanced low-temperature co-fired ceramic (LTCC) method. The electrical properties and bonding strength of the multilayers were associated with the interface morphologies between the piezoelectric and silver-electrode layers. Usually, the inner silver electrodes are fabricated by sintering silver paste in multi-layer stacks. To improve the interface bonding strength, piezoelectric powders of 0.90PZT-0.05PMS-0.05PZN with an average particle size of $23{\mu}m$ were added to silver paste to form a gradient interface. SEM observation indicated clear interfaces in multilayer ceramics without powder addition. With the increase of piezoelectric powder addition in the silver paste, gradient interfaces were successfully obtained. The multilayer ceramics with gradient interfaces present greater bonding strength as well as excellent piezoelectric properties for 30~40 wt% of added powder. On the other hand, over addition greatly increased the resistance of the inner silver electrodes, leading to a piezoelectric behavior like that of bulk ceramics in multilayers.

• Smart Structures and Systems
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• v.14 no.3
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• pp.267-284
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• 2014

This paper aims to present the analytical solutions of 2-2 cement based piezoelectric transducers in series electrically based on the theory of piezo-elastic dynamics. The solutions of two different kinds of 2-2 cement based piezoelectric transducers under external harmonic load are obtained by using the displacement method. The effects of electrical connection of piezoelectric layers, loading frequency, thickness and distance of piezoelectric layers on the characteristics of the transducers are discussed. Comparisons with other related experimental investigations are also given, and good agreement is found. The proposed 2-2 cement based piezoelectric transducers have a great potential application in monitoring structural health in civil engineering and capturing mechanical energy or monitoring train-running safety in railway system and traffic safety in road system.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.15-21
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• 1999

This study investigates the free and forced vibration characteristics of an annular piezoelectric motor stator constructed of two piezoelectric material layers and one stainless steel layer. The annular piezoelectric motor stator is subjected to a travelling load produced by piezo drive electrical voltage input to the two piezoelectric layers. The stator is modeled as an annular laminated plate based on the classical plate theory and the governing equations are derived via Hamilton's variational principle. Variation of the free vibration characteristics as a function of several design parameters has been studied and based on this result, the forced vibration responses to the input electricity of various frequencies and magnitudes are investigated. The obtained results will provide an important criterion, a priori, in the design of piezoelectric motors.

• Smart Structures and Systems
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• v.14 no.5
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• pp.961-980
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• 2014

Based on the general theory of elasticity, the static behavior of 2-2 cement-based piezoelectric curved composites is investigated. The actuator consists of 2 cement layers and 1 piezoelectric layer. Considering the electrode layer between the cement layer and the piezoelectric layer as the elastic layer, the exact solutions of the mechanical and electrical fields of the curved composites are obtained by utilizing the Airy stress function method. Furthermore, the theoretical results are compared with the FEM results and good agreements (with almost no error) are obtained, thus proving the validity of this study. Furthermore, the influence of certain parameters is discussed, which can help to get the desired displacements and stresses. Finally, it is seen that the analytical model established in this paper works well, which could benefit the design of this kind of cement-based smart devices.

• Smart Structures and Systems
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• v.15 no.5
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• pp.1345-1362
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• 2015

The present paper deals with the free vibration analysis of the functionally graded solid and annular circular plates with two functionally graded piezoelectric layers at top and bottom subjected to an electric field. Classical plate theory (CPT) is used for description of the all deformation components based on a symmetric distribution. All the mechanical and electrical properties except Poisson's ratio can vary continuously along the thickness direction of the plate. The properties of plate core can vary from metal at bottom to ceramic at top. The effect of non homogeneous index of functionally graded and functionally graded piezoelectric sections can be considered on the results of the system. $1^{st}$ and $2^{nd}$ modes of natural frequencies of the system have been evaluated for both solid and annular circular plates, individually.

• Advances in aircraft and spacecraft science
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• v.10 no.2
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• pp.179-202
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• 2023

This article presents a numerical analysis to investigate the natural frequencies and harmonic response of a perforated cantilever beam attached to two layers of piezoelectric materials by using the finite element method for the first time. The bimorph piezoelectric is composed of 3 layers; two of them at the outer are piezoelectric, and the inner isotropic material. A higher order 3-D 20-node solid element that exhibits quadratic displacement behavior is exploited to discretize the isotropic layer, and coupled piezoelectric 3D element with twenty nodes is used to mesh the top and bottom layers. CIRCU94 element is added to act as a resistor part of the model. The proposed model is validated with previous works. The numerical parametric studies are presented to illustrate the effects of perforation geometry, the number of rows, the resistance on the natural frequencies, frequency response, and power. It is found that the thickness has a positive relationship with the natural frequency. Perforations help in producing higher voltage, and the best shape is rectangular perforations, and to produce higher voltage, two rows of rectangular perforations should be applied.