• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1757-1763
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• 2010

Flywheel energy storage system (FESS) is defined as a high speed rotating flywheel system that can save surplus electric power. The FESS is proposed as an efficient energy storage system because it can accumulate a large amount of energy when it is operated at a high rotating speed and no mechanical problems are encountered. The FESS consists of a shaft, flywheel, motor/generator, bearings, and case. It is difficult to simulate rotor dynamics using common structure simulation programs because these programs are based on the 3D model and complex input rotating conditions. Therefore, in this paper, a program for the FESS based on the 2D FEM was developed. The 2D FEM can model easier than 3D, and it can present the multi-layer rotor with different material each other. Stiffness changing of the shaft caused by shrink fitting of the hub can be inputted to get clear solving results. The results obtained using the program were compared with those obtained using the common programs to determine any errors.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5B
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• pp.453-461
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• 2009

In this study, a dynamic numerical model, FLDWAV, is used for analyzing the backwater effect of flood stage in YeongWeol station, which is located on the confluence upstream where Pyeongchang river joins Han river. Given various inflow discharges of both main stream and tributary, the feasible stage-discharge relationships at the YeongWeol station and the upstream range of the backwater effect were computed. The results show that the relationships are completely different according to each of the inflow discharges from tributary and the maximum difference of stage is about 4.0 m. Therefore, the development of a single relationship of stage and discharge is very difficult problem in the zone of backwater effect. The increase of stage in the junction due to the lateral inflow has an effect on upstream stage up to about 8.0 km. The well-calibrated and verified dynamic wave routing model will be a useful tool for the flood forecast in the zone of backwater effect rather than conventional hydrological routing model.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.17-24
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• 2004

This paper established the dynamic model of a flexible Timoshenko beam with geometrical nonlinearities subject to large overall motions by using the finite element method. The equations of motion are derived by using Hamilton principle based on expressing the kinetic and potential energies of the flexible beam in terms of generalized coordinates. The nonlinear constraint equations are adjoined to the system equations of motion by using Lagrange multipliers.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.1974-1984
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• 1994

This paper presents a relative coordinate formulation for constrained mechanical systems. Relative coordinates are defined along degrees of freedom of a joint. Graph theoretic analyses are performed to identify topological paths in mechanical systems. Cut constraints are generated to handle closed loop systems. Equations of motion are derived in the Cartesian space and transformed to the joint space. Relative generalized coordinates are corrected to satisfy the cut constraints by a parametrizatiom method.

• Journal of Ocean Engineering and Technology
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• v.6 no.2
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• pp.55-70
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• 1992

트림변화에 의해서 발생하는 선체 구조응답을 고찰, 계산 결과를 요약하였다. 본 고찰로 부터 같은 크기의 선수, 선미 트림상태일지라도 많은 차이를 보였다. 이에는 중량분포의 효과가 특히 크게 작용함을 밝히었다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.315-319
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• 1993

A dynamic modeling, analysis, and optimum design issuess for the Hybrid type of robot are addressed. The dynamic modeling can be used to describe acceleration and velocity properties of the system explicitly in terms of the actuating forces is coded in C language based on the kinematic influence coefficients(KIC). By using this modeling simulation, the actuating forces needed for the robot follows the given trajectory are calculated. Also, for the design concept, the optimum geometric configuration of the system that minimizes the maximum actuating forces is found by using the optimization techique.

• Journal of the korean Society of Automotive Engineers
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• v.10 no.2
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• pp.39-45
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• 1988

The analytical model of an engine mount system with six degrees of freedom is identified using the modal parameters obtained from the experimental modal analysis. The structural parameters, mass moment of inertia of the engine block and stiffness of the rubber mounts, of the engine mount system are determined by using the condition that the estimated model parameters should satisfy the corresponding eigenvalue problem. The simulated modal parameters of the identified analytical model are in good agreement with the measured modal parameters.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.937-942
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• 1993

This paper extends the authors' prior work on the regulation of flexible space structures via partial feedback linearization (PFL) methods to articulated systems. Recursive relations introduced by Jain and Rodriguez are central to the efficient formulation of models via Poincare's form of Lagrange's equations. Such models provide for easy construction of feedback linearizing control laws. Adaptation is shown to be an effective way of reducing sensitivity to uncertain parameters. An application to a flexible platform with mobile remote manipulator system is highlighted.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.349-353
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• 1992

The purpose of this paper is to develop methods for the dynamic analysis of multibody system that consist of interconnected rigid and deformable component. The equations of motion are derived by using the Lagrange's equation and finite element theory for the elastic mechanism systems. The type of equation of motion is the differential algebraic equation included kinematic nonlinear algebraic equation. The generalized coordinate partitioning method is used for solving this equation. To show the validity of this analysis solver, couple of models were canalized and those results were compared with the commercial package(ADAMS).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.951-952
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• 2009