• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.624-629
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• 2003

In this paper, broadband shunt technique for increasing transmission loss is experimentally investigated. Piezoelectric shunt damping is studied using resonant shunt circuit and negative capacitor shunt circuit. A resonant shunt circuit is implemented by using a resistor and inductor. Negative Capacitor shunt damping is similar in nature to resonant shunt damping techniques, as a single piezoelectric material is used to dampen multi-mode. Performance of both methods is experimentally studied for noise reduction. This is based upon SAE J1400 test method and a transmission loss measurement system is provided for it. This paper will present the test setup fer transmission loss measurement and the tuning procedure of shunt circuits. Finally the results of sound transmission tests will be shown.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.918-921
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• 2005

According to the mechanical-electrical coupling characteristics and the electrical Impedance property of resistor-inductor-capacitor(RLC) series resonant circuit, the mechanical impedance analysis of a bimorph piezoceramic patch shunted with a series RLC resonant circuit is conducted. The displacement transfer function of a cantilever beam bonded with a piezoelectric shunt damping module is deduced in the case of single mode vibration of the beam. By the use of vibration damping theory of tuned mass damper system, the parameter optimization of piezoelectric shunt damping system is performed. The optimal resonant state of the shunting circuit can be obtained when the resister and conductor are optimally adjusted. Test results show that the vibration control effect as well improved with optimized piezoelectric shunt system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.127-132
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• 2001

In this paper, transmitted sound reduction performance of smart panels is studied according to different piezoelectric materials with piezoelectric shunt damping. Peizo-damping is implemented by using a newly proposed tuning method. This method is based on electrical impedance model and maximizing the dissipated energy at the shunt circuit. By measuring the electrical impedance at the piezoelectric patch bonded on a structure, an equivalent electrical model is constructed near the system resonance frequency. After shunting elements are connected to the equivalent circuit, the shunt parameters are optimally searched based on the criterion of maximizing the dissipated energy at the shunt circuit. Transmitted sound reduction performance is compared according to different piezoelectric materials with peizo-damping. Two piezoelectric materials are selected: PZT-5 and QuickPack IDE actuator. When resonant shunt circuit is considered, the use of PZT-5 exhibited the good sound reduction performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.77-80
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• 2008

In this paper the electromagnetic shunt damper was newly employed for vibration suppression of the flexible structures. The electromagnetic shunt damper consists of a coil and a permanent magnet. The ends of the coil were connected to the RLC shunt circuit. The numerical solutions of resonant frequency of the shunt circuits were calculated by using Pspice. The vibration and damping characteristics of the flexible beams with the electromagnetic shunt damper were investigated by tuning the circuit parameters. Also, the effect of the magnetic intensity on the shunt damping was studied with the variation of the gap between the aluminum beam and the permanent magnet. Present results show that the magnet shunt damper can be successfully applied to reduce the vibration of the flexible structures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.328.2-328
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• 2002

General modeling of a resonant shunting damper has been made Iron piezoelectric sensor/actuator equation. It is found that an additional damping, which is augmented to a system, is generated by the shunt damping effect The transfer function of the tuned electrical absorber is derived for both series and parallel shunt circuit. The governing equations and associated boundary conditions are derived using Hamilton's Principle. The shunt voltage equation is also derived from the charge generated in PZT due to beam vibration. The frequency response function of the obtained mathematical model is compared with that of the tuned eledtrical absorber and experimental work. The vibration amplitude is reduced about 15 dB at targeted second mode frequency.

• Journal of Mechanical Science and Technology
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• v.16 no.1
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• pp.1-12
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• 2002

In this study, a passive suppression scheme for nonlinear flutter problem of composite panel, which is believed to be more reliable than the active control methods in practical operations, is proposed. This scheme utilizes a piezoelectric inductor-resistor series shunt circuit. The finite element equations of motion for an electromechanically coupled system is derived by applying the Hamilton\\`s principle. The aerodynamic theory adopted for the present study is based on the quasi-steady piston theory, and von-barman nonlinear strain-displacement relation is also applied. The passive suppression results for nonlinear panel flutter are obtained in the time domain using the Newmark-$\beta$ method. To achieve the best damping effect, optimal shape and location of fille piezoceramic (PZT) patches are determined by using genetic algorithms. The effects of passive suppression are investigated by employing in turn one shunt circuit and two independent shunt circuits. Feasibility studies show that two independent inductor-resistor shunt circuits suppresses flutter more effectively than a single shunt circuit. The results clearly demonstrate that the passive damping scheme that uses piezoelectric shunt circuit can effectively attenuate the flutter.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.468-470
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• 1995

In this paper, a series compensator with a resonant LC circuit and a shunt compensator with the resonant circuit are compared based on the respective rating of its circuit elements. The rating are calculated over a range of compensation and over a range of bus angle. The components ratings are expressed in a per unit values. The results of this study can be easily converted to actual MVA by a simple change in scale. The methodology presented to rate the various components within the system will help to determine the feasibility of various FACTS devices in costs.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.228-233
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• 2002

General modeling of a resonant shunting damper has been made from piezoelectric sensor/actuator equation. It is found that an additional damping, which is augmented to a system, is generated by the shunt damping effect. The transfer function of the tuned electrical absorber is derived for both series and parallel shunt circuit. The governing equations and associated boundary conditions are derived using Hamilton's Principle. The shunt voltage equation is also derived from the charge generated in PZT due to beam vibration. The frequency response function of the obtained mathematical model is compared with that of the tuned electrical absorber and experimental work. The vibration amplitude is reduced about 15 dB at targeted second mode frequency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.541-544
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• 2005

In this paper, admittance is introduced to represent electro-mechanical characteristics of piezoelectric structures and to predict the performance of piezoelectric shunt system. Finite element method is used to obtain numerical admittance. In order to illuminate the effect of noise reduction in the shunt system, two experimental setups were constructed. One is for matching the resonant shunt damping. The other is a standard test setup according to SAE J1400 used to measure the transmission loss for the smart panel with shunt circuit. Shunt performance and noise reduction of smart panel are realized by these two experiments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.49-56
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• 2001

The possibility of a noise reduction of piezoelectric single Panels is experimentally studied. Piezoelectric single panel is basically a plate structure on which piezoelectric patch with shunt circuit is mounted. The use of piezoelectric shunt damping can reduce the transmission at resonance frequencies of the panel structure. Piezo-damping is implemented by using a newly proposed tuning method. This method is based on electrical impedance model and maximizing the dissipated energy at the shunt circuit. By measuring the electrical impedance at the piezoelectric patch bonded on a structure, an equivalent electrical model is constructed near the system resonance frequency. Resonant shunt circuit for piezoelectric shunt damping is composed of register and inductor in series, and they are determined by maximizing the dissipated energy throughout the circuit. The transmitted noise reduction performance of single Panel is tested on an acoustic tunnel. The tunnel is a tube with a square cross section and a loud speaker is mounted at one side of the tube as a sound source. Panels are mounted in the middle of the tunnel and the transmitted sound pressure across Panels is measured. By enabling the piezoelectric shunt damping noise reduction is achieved at the resonance frequencies as well. Piezoelectric single panel with piezoelectric shunt damping is a promising technology for noise reduction in a broadband frequency.