• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.2
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• pp.67-73
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• 2003

In this paper, the impedance of a piezoelectric transducer is calculated using the three-dimensional finite element method. The validity of numerical routine is confirmed experimentally. Using this numerical routine, the effects of material coefficients on piezoelectric actuators characteristics are analyzed. The material constants, which make significant effects, are selected and the relations between material constants are studied. Using these processes, three variables of material constants for a piezoelectric transducer are selected and the design sensitivity method is adopted as an inversion scheme. The validity of the inversion scheme for a piezoelectric transducer is confirmed by applying the proposed method to the sample piezoelectric transducer.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.225-228
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• 2001

A new three-dimensional thin shell element for the structure containing an integrated distributed piezoelectric sensor and actuator is proposed. A finite element formulation for the static response of the shell with piezoelectric sensor／actuator is derived. The assumed strain formulation and the bubble function improves the performance of the shell element. The verification through the calculation of the static response for the piezoelectic bimorph beam shows that the results agree with those from the theoretical analysis very well.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.12
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• pp.1347-1355
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• 2009

This paper demonstrates the validity of spectral element analysis for modeling the high-frequency dynamic behaviors of a beam with a surface-bonded piezoelectric wafer through a laboratory test. In the spectral element analysis, the high-frequency electro-mechanical interaction can be considered properly with relatively low computational cost compared to the finite element analysis. In the verification test, a cantilever beam with a surface-bonded piezoelectric wafer is forced to be in steady-state motion by exerting the harmonic driving voltage signal on the piezoelectric wafer. A laser scanning vibrometer is used to obtain the overall dynamic responses of the structure such as resonance frequencies, the associated mode shapes, and frequency response functions up to 20 kHz. Then, these dynamic responses from the test are compared to those computed by the spectral element analysis. A two-dimensional finite analysis is conducted to obtain the asymptotic solutions for the comparison purpose as well.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.105-111
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• 2009

Dielectric breakdown in piezoelectric ceramics is analyzed by using the three dimensional J integral. The J integral is shown to be a path-independent surface integral for a conductive tubular channel in a piezoelectric material. J integrals are also numerically calculated for conductive defects and tubular channels in piezoelectric ceramics through finite element analysis.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.12
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• pp.1124-1128
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• 2005

New piezoelectric actuator design, which can reduce the number of the stacking layer without lowering the piezoelectric displacement, is suggested in this work. Each layer of the new designed multilayer actuator has the same electrode pattern as the cross-sectioned layer of the existing multilayer actuator has. The piezoelectric displacement was calculated by Finite-Element Method (FEM) analysis. The maximum piezoelectric displacement of the new-designed actuator with 13 layers was calculated to be almost same value (55.9 ${\mu}m$) as that of the existing actuator with 25 layers(60.1 ${\mu}m$).

• Smart Structures and Systems
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• v.24 no.3
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• pp.379-390
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• 2019

In this research, we propose an energy harvesting structure with a flexible blade element vibrating at its first mode to maximize the power output of the piezoelectric material. For this purpose, a piezoelectric patch was attached on the blade element used in a small-scale wind turbine, and air load was applied with a suitable angle of attack in the stall zone. The aerodynamic load created by air excitation vibrates the blade element in its first natural frequency and maximizes the voltage output of the piezoelectric patch. The variation of power outputs with respect to electrical resistance, air speed, and extra mass is experimentally investigated for various cases. An analytical model is constituted using a single-mode blade element with piezoelectric patch dynamics, and the power outputs of the obtained model are compared with experimental results.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.2
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• pp.42-49
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• 2006

In this paper, an efficient piezoelectric passive damper is newly devised to suppress the multi-mode vibration of plates. To construct the passive damper, the piezoelectric materials are utilized as energy transformer, which can transform the mechanical energy to electrical energy. To dissipate the electrical energy transformed from mechanical energy, multiple resonant shunted piezoelectric circuits are applied. The dynamic governing equations of a coupled electro-mechanical piezoelectric with multiple piezoelectric patches and multiple resonant shunted circuits is derived and solved for the one edge clamped plate. The equations of motion of the piezoelectrics and shunted circuits as well as the plate are discretized by finite element method to estimate more exactly the effectiveness of the piezoelectric passive damper. The method to find the optimal location of a piezoelectric is presented to maximize effectiveness for desired modes. The electro-mechanical coupling term becomes important parameter to select the optimal location.

• Smart Structures and Systems
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• v.12 no.5
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• pp.579-594
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• 2013

A new enthalpy - based procedure for the homogenization of the electromechanical material parameters of composite piezoelectric modules with integrated electrodes is presented. It is based on a finite element (FE) modeling of the latter's representative volume element (RVE). In contrast to most previously published homogenization approaches that are based on averaged quantities, the presented method uses a direct evaluation of the electromechanical enthalpy. Hence, for the linear orthotropic piezoelectric composite behavior full set of elastic, piezoelectric, and dielectric material parameters, 17 load cases (LC) are used where each load case leads directly to one material parameter. This gives the possibility to elaborate a very strict and easy to program processing. In conjunction with the 17 LC, the enthalpy - based homogenization is particularly suitable for laminated composite piezoelectric modules with integrated electrodes. In this case, the electric load has to be given at the electrodes rather than at the RVE FE model boundaries. The proposed procedure is validated through its comparison to literature available results on a classical 1-3 piezoelectric micro fiber (longitudinally polarized) reinforced composite and a $d_{15}$ shear piezoelectric macro-fiber (transversely polarized) composite module.

• Smart Structures and Systems
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• v.4 no.5
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• pp.565-582
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• 2008

This paper presents a feasibility study of flexible piezoelectric paint for use in wide-band low-profile surface-mount or embeddable ultrasonic sensor for in situ structural health monitoring. Piezoelectric paint is a piezoelectric composite with 0-3 connectivity. Because of its ease of application, piezoelectric paint can be readily fabricated into sensing element with complex pattern. This study examines the characteristics of piezoelectric paint in acoustic emission signal and ultrasonic guided wave sensing. A series of ultrasonic tests including pitch catch and pencil break tests were performed to validate the ultrasonic wave sensing capability of piezoelectric paint. The results of finite element simulation of ultrasonic wave propagation, and acoustic emission generated by a pencil lead break on an aluminum plate are also presented in this paper along with corresponding experimental data. Based on the preliminary experimental results, the piezoelectric paint appears to offer a promising sensing material for use in real-time monitoring of crack initiation and propagation in both metallic and composite structures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.680-683
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• 1997

In this paper, the multilayer actuator is investigated by using the finite element method. The material is taken to be piezoelectric. The capacitor and interdigital wlfloating type actuator are compared to the stress field distribution under the uniform electric field. As the length of the floating electrode in the interdigital wlfloating actuator changes, the stress field around the edge of electrode is studied.