• Journal of the Korean Society for Marine Environment & Energy
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• v.20 no.2
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• pp.63-75
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• 2017

In offshore environment, an accurate estimation of a wave-structure interaction has been an important issue for safe and cost effective design of fixed and floating offshore structures exposed to a harsh environment. In this study, a wave-structure interaction around a circular column was investigated with regular waves. To simulate 3D two-phase flow, open source computational fluid dynamics libraries, called OpenFOAM, were used. Wave generation and absorption in the wave tank were activated by the relaxation method, which implemented in a source term. To validate the numerical methods, generated Stokes 2nd-order wave profiles were compared with the analytic solution with deep water condition. From the validation test, grid longitudinal and vertical sizes for wave length and amplitude were selected. The simulated wave run-up and wave loads on the circular column were studied and compared with existing experimental data.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.342.1-342
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• 2001

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.5
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• pp.156-168
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• 2022

The design and construction are carried out to improve the structural stability of caisson breakwaters by installing new caissons on the front or rear of old caissons. The wave forces acting on caisson are excessively calculated by the resonance of fluid existing between the old caisson and the new caisson in the numerical analysis using potential flow. In this study, we used the damping zone option in ANSYS AQWA program to analyze the wave forces acting on individual caissons according to the interaction effects between the incident wave and the caisson. By applying the damping zone option to the fluid in which resonance occurs, the wave forces acting on individual caissons were calculated by the change of damping factor. In addition, the wave force characteristics acting on individual caissons were analyzed for the different distances between caissons in the frequency domain analysis.

• Journal of computational fluids engineering
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• v.5 no.3
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• pp.16-22
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• 2000

In the present study a method of computing fluid-structure interaction is presented to simulate the deformation shape of an oil fence which is used to contain or to divert the split oil in sea water. The computation is performed by taking into account of the force and moment balance in each computational element of the oil fence. The forces and moments acting on each element of the structure is computed from the flow analysis, which in turn is used to predict deformed shape of the structure until the procedure converges. The flexibility of the oil fence was also considered in the analysis. It is shown from the present study that the predicted deformed shapes agree quite well with the available experiment data.

• Computational Structural Engineering
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• v.7 no.2
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• pp.4-10
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• 1994

컴퓨터 성능과 전산유체역학 분야는 지속적으로 발전하고 있으므로 이에 따라 유체의 유동장은 더욱 정확하고 상세히 묘사할 수 있게 될 것이며, 더불어 ALE유한요소법 등과 같은 유체-구조 상호작용해석 기법이 발전해 나갈 것이다. 따라서, 현재 수행되고 있는 풍동실험은 다양한 모형제작으로 인한 비용문제와 완성된 모형의 정밀도 문제, 각 모형에 대한 반복적인 실험과정 등 적절한 설계형상을 선택하는 과정에서 효율성이 낮은 경우가 많으므로 수치해석에 의한 내풍안정성 평가과정을 병행함으로써 실험의 효율성이 낮은 부분을 보완, 최소화할 수 있을 것이다. 특히 적은 비용 및 시간내에 개략적인 내풍안정성 파악이 요구되는 개념설계 및 초기설계단계에 근사적인 내풍안정성 검토 기술로서 결과적으로 활용될 수 있을 것이다. 또한 수치해석기법의 가장 큰 장애요인었던 유체 유동장의 모사정도가 향상됨에 따라 수치해석에 의한 장대구조물의 내풍안정성해석은 앞으로 상당한 발전이 있을 것으로 전망된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2A
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• pp.117-122
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• 2012

Coastal structures, constructed for preventing coastal slope erosion, often causes the scour on the boundary between the coastal structure and the sea-bed, which might lead to collapse of coastal structures. To prevent the collapse, the usual upright block type coastal structures can be modified to other forms or systems of coastal structures. To validate the performance of the proposed systems, it is necessary to conduct high cost hydraulic experiments. If numerical modeling can be performed prior to the hydraulic experiments and the performance of the proposed systems is analyzed numerically in advance, the expenses can be reduced significantly by optimizing the number of cases for conducting the experiments. In this study, a fluid-structure interaction analysis procedure is proposed for modeling the hydraulic experiments of costal structures using the finite element package, LS-DYNA. As can be found in the usual hydraulic experiments, fluid velocities of potential scour locations are monitored and analyzed in detail for four types of coastal structures, block, step, trapezoid and rubble mound.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.1
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• pp.23-34
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• 1998

A dynamic fluid-structure-soil interaction analysis method is developed to investigate the effects of translational and/or rocking motions on the seismic response of flexible rectangular liquid storage tanks founded on the deformable ground. The governing equation for the dynamics of 3-D rectangular tanks subjected to the translational and/or rocking motion is abtained by applying Rayleigh-Ritz method. The dynamic stiffness matrices of a rigid rectangular foundation resting on the surface of a stratum overlaid bedrock are calculated by hyperelement method. The seismic responses of 3-D flexible tank model founded on the deformable ground is calculated by combining the governing equation for the fluid-tank system with the dynamic stiffness matrix of th rigid surface foundation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.463-472
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• 1994

A method of stochastic response analysis of base-isolated fluid-filled pool structures subject to random ground excitations is studied. Fluid-structure interaction effects between the flexible walls and contained fluid are taken into account in the form of added mass matrix derived by FEM modeling of the contained fluid motion. The stationary ground excitation is represented by Modified Clough-Penzien spectral model and the nonstationary one is obtained by imposing an envelope function on the stationary one. The stationary and nonstationary response statistics of the two different isolation systems are obtained by solving the governing Lyapunov covariance matrix differential equations.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.3
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• pp.92-98
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• 2006

In this study, the behavior characteristics of a hydrostatic thrust bearing used in hydraulic equipment was analyzed using a commercial finite element program, ADINA. The solid domain was modeled with the fluid domain simultaneously to solve the fully coupled problem, because this is a problem where a fully coupled analysis is needed in order to model the fluid-structure interaction(FSI). The results such as bearing deformation, stress, film thickness and lifting bearing force were obtained through FSI analysis, and then they were compared with the results calculated from the classical method, a single step sequential analysis. It was found that the result difference between two analyses was increased according to the injection pressure. Therefore, in case of high pressure loading, it is desirable to conduct the FSI analysis to examine the deformation characteristics of a hydrostatic slipper bearing.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.443-450
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• 2002

본 논문에서는 미국토목학회(ASCE)의 사장교에 대한 첫번째 벤치마크 문제를 이용하여 제어-구조물 상호작용을 고려한 새로운 반능동 제어 기법을 제안하였다. 이 벤치마크 문제에서는 2003년 완공 예정으로 미국 Missouri 주에 건설 중인 Cape Girardeau 교를 대상 구조물로 고려하였다. Cape Girardeau 교는 New Madrid 지진구역에 위치하고, Mississippi 강을 횡단하는 주요 교량이라는 점 때문에 설계단계에서부터 내진 문제에 대하여 자세하게 고려되었다. 상세 설계 도면을 기반으로 하여 교량의 전체적인 거동 특성을 정확하게 나타낼 수 있는 3차원 모델이 만들어졌고, 사장교의 제어 성능에 관련된 평가 기준이 수립되었다. 본 연구에서는 제어 가능한 유체 감쇠기에 속하는 MR 유체 감쇠기를 제어 장치로 제안하였고, 기존 연구에서 MR 유체 감쇠기를 포함한 구조물의 제어에 효율적이라고 검증된 clipped-optimal 알고리듬을 제어 알고리듬으로 사용하였다. 또한, 실제 규모의 MR 유체 감쇠기 실험 결과를 이용하여 수치해석에 이용할 수 있는 동적 모델을 개발하였다. MR 유체 감쇠기는 제어 가능한 에너지 소산장치이며 구조물에 에너지를 가하지 않기 때문에 제안된 제어 기법은 한정입출력 안정성이 보장된다. 수치해석을 통해, MR 유체 감쇠기를 이용한 반능동 제어 기법이 사장교의 응답 감소에 효과적인 방법임을 증명하였다.