• Journal of Power System Engineering
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• v.14 no.6
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• pp.67-74
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• 2010

Many tanks are installed in ship and marine structures. They are often in contact with inner or outer fluid, like ballast, fuel and cargo tanks. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance with exciting force of engine and propeller. Vibration characteristics of these thin walled tanks in contact with fluid near engine and propeller are strongly affected by added mass of containing fluid. Therefore it is essentially important to estimate the added mass effect to predict vibration of the tanks. Many authors have studied vibration of cylindrical and rectangular tanks containing fluid. Few research on dynamic interaction among tank walls through fluid are reported in the vibration of rectangular tanks recently. In case of rectangular tanks, structural coupling between adjacent panels and effect of vibration modes of multiple panels on added mass have to be considered. In the previous report, A numerical tool of vibration analysis of a 3-dimensional tank is developed by using finite element method for plates and boundary element method for fluid region. In this paper, the coupling effect between panels of a tank on added mass of containing fluid, the effect of structural constraint between panels on each vibration mode for fluid region and mode characteristics in accordance with changing breadth of the plates are investigated numerically and discussed.

• The Journal of the Acoustical Society of Korea
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• v.13 no.2
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• pp.60-67
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• 1994

This is the first of two companion papers which suggests the algorithm of the combined Finite Element Method and Infinite Element Method for the analysis of the axi-symmetric acoustic transducer in the open boundary. Using the algorithm, the numerical analysis for the transducer radiation impedance, directivity, and coupling effect between transducer elements are also conducted. In the second paper, the wideband array transducer is designed and its acoustic characteristics are examined on the basis of the results of the first paper.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.5
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• pp.307-314
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• 2023

This study aims to evaluate the blast performance of shear and flexure failure modes of reinforced concrete columns using finite-element analyses. To accomplish this goal, finite-element models of flexure- and shear-governed columns were developed and validated using previous experimental results. A blast simulation model was developed using a coupling-modeling method, and the modeling method was applied to the validated-column models. Blast responses were obtained for various blast loading scenarios, and the blast performance was determined using limits based on ductility and axial loading capacity.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.8
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• pp.543-556
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• 2016

In this work, an insulated coupling test machine for a 5-MW-class wind turbine was designed and developed, along with the public performance testing of a 3-MW-class wind turbine. The results of the device design, development requirements, functional considerations, structural vibration analysis, and the evaluation of the insulated coupling test machine are presented in this study. For the coupling models, thick fiberglass composite pipe insulation, fabricated by filament winding, was considered. Results of three-dimensional finite element analysis conducted using both solid element and shell element modeling were analyzed and compared, considering the effect of thickness. In addition, results from the nonlinear finite element analysis of multiple leaf springs of the laminated disk pack structure were verified and compared with experimental data.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.374-378
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• 2014

The piezoelectric materials convert from mechanical energy to electrical energy. The piezoelectric materials are used in various engineering applications such as piezoelectric ultrasonic actuators. Since the piezoelectric coupling characteristics of the actuator systems should be considered at the initial design stage, it is essential to analyze the piezoelectric coupling characteristics of the ultrasonic actuators. In this study, we analyzed the electromechanical characteristics of piezoelectric stacked actuator using the equivalent circuit model with modal mass stiffness parameters. It was compared the admittance of piezoelectric stack actuators with the analytical circuit model and the finite element model. Also, the coupling coefficient of piezoelectric stack actuator was discussed according to the number of stacks of actuators.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.366-369
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• 2002

Two artificial neural networks (ANN) are used to model the electric coupling probe in the combline resonators. One is used to analyze and synthesize the electric probe, and the other is used to correct errors between the results of the analysis and the synthesis ANNs and the fabrication results. The ANNs for the analysis and the synthesis of the electric probe are trained using the physical dimensions of the electric probe and the corresponding coupling bandwidth which is obtained using the finite element method. The ANNs for the error correction are trained using a very small set of the measurement results. Once trained, the ANN models provide the correct result approaching the accuracy of the measurement. The results from the ANN models show fairly good agreement with those of the measurement and they can be used as good initial design values.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.112-114
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• 2002

Coupling drives are shown to be appliacable to a wide range of control variables. This paper develops three dimensional theory of the eddy current coupling. It compares experimental results obtained on 5-Hp inductor type eddy current coupling with the theoretical computations. The flux density distributions are also presented using 3-D Finite element analysis.

• The KSFM Journal of Fluid Machinery
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• v.17 no.4
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• pp.70-75
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• 2014

In this paper a analysis method is presented to obtain the steady state dynamic response from the finite element based equations of a rotor-bearing system with initial deflection. The method has been applied to analyze the dynamic response of the two-shaft rotor-bearing system with rigid coupling offset in a heavy duty gas turbine-generator. Bumps in the dynamic response of each rotor system have been observed at each critical speed due to the effect of initial deflection for rigid coupling offset. And, the dynamic responses have been shown to reduce for operating condition changes from cold to hot.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.66-75
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• 1997

Sound transmission from the luggage comparment into the car cabin is important in the viewpoint if exhaust and road noises of passenger cars. In this paper, acoustic modal coupling between passenger and luggage compartments through loudspeaker holes at parcel shelf is dealt with for a sedan type passenger car with rigid rear seat. For these purposes, a half-scaled model car is tested and computed by the indirect BEM. Predicted acoustic transfer functions are compared with experimental ones and they agree reasonably well. It is found that the fore-aft resonance frequencies of the passenger cavity in the absence of coupling holes are tend to shift to higher frequencies when the luggage compartment is coupled to the passenger cavity.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.291-293
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• 1997

The external magnetic field which is applied to the superconducting wire generates coupling loss. Analytical method has been used for the calculation of the coupling loss. This paper calculates the coupling loss that is generated in the matrix by the external magnetic field. Two-dimensional Finite Element Method has been used for the calculation.