• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1995년도 봄 학술발표회 논문집
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• pp.122-129
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• 1995

The seismic behavior of a rectangular liquid container with high damping laminated rubber bearing is investigated through the scaled model tests. The results are compared with those for non-isolated model, and those by analytical methods. It is shown that the optimum dynamic properties of isolation system can reduce the acceleration response in the superstructure significantly and prevent the amplification of sloshing height.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.33-34
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• 2007

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.89-94
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• 2010

액체로켓 기체공급계는 추진제를 요구되는 유량, 온도, 압력으로 엔진에 공급하여야 한다. 이를 위한 정상상태의 공급특성은 기존의 열역학 및 열전달, 유체역학 이론을 적용하여 해석하며 방법론이 잘 정립되어 있다. 발사체의 비행 중에 발생하는 탱크와 공급배관에서의 추진제의 진동은 정상상태의 공급특성을 변하게 하며 추진제공급 요구조건을 만족시키지 못하게 한다. 이러한 진동을 발생시키는 것으로서 발사체의 가속도로 인한 슬로싱 및 엔진의 추력섭동에 의해 배관 내 추진제가 진동하는 포고 불안정이 있다. 포고와 슬로싱에 의한 발사체 제어와 구조측면에서 미치는 영향에 대해서는 기존에 많은 연구가 있으나 추진제 공급특성에 미치는 영향에 대해서는 잘 알려져 있지 않다. 본 연구에서는 추진제의 진동이 엔진으로의 추진제 공급에 미치는 영향을 기존 자료를 이용하여 살펴보고 진동을 제어하기 위한 기구를 살펴본다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.275-283
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• 1999

To predict the dynamic behavior of the cylindrical liquid storage tank subjected to seismic ground motion three dimesional analysis with liquid-structure interaction must be performed, In this study a three dimensional dynamic analysis method over the frequency domain using FE-BE coupling technique which combines the efficiency of the boundary elements for liquid with the versatility of the finite shell elements for tank. The liquid region is modeled using boundary elements which can counter the sloshing effect at free surface and the structure region the tank itself is modeled using the degenerated finite shell elements. At the beginning of the procedure the equivalent mass matrix of the liquid is generated by boundary elements procedure. Then this equivalent mass matrix is combined with the mass matrix of the structure to produce the global mass matrix in the equation of the motion of fluid-structure interaction problem In order to demonstrate the accuracy and validity of the developed method the numerical results re compared with the previous studies. Finally the effects of the fluid-structure interaction on the natural frequency and dynamic response of the system are analyzed.

• Coupled systems mechanics
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• 제8권1호
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• pp.19-38
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• 2019

The influence of torsional rigidity of hinged flexible appendage on the linear dynamics of flexible spacecrafts with liquid on board was analyzed by considering the spacecraft's main body as a rigid tank, its flexible appendages as two elastically supported elastic beams, and the onboard liquid as an ideal liquid. The meniscus of the liquid free surface due to surface tension was considered. Using the Lagrangian of the spacecraft's main body (rigid tank), onboard liquid, and two beams (flexible appendages) in addition to assuming the system moved symmetrically, the coupled system frequency equations were obtained by applying the Rayleigh-Ritz method. The influence of the torsional rigidity of the flexible appendages on the spacecraft's coupled vibration characteristics was primary focus of investigation. It was found that coupled vibration modes especially that of appendage considerably changed with torsion spring parameter ${\kappa}_t$ of the flexible appendage. In addition, variation of the main body displacement with system parameters was investigated.

• 전산구조공학
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• 제9권1호
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• pp.55-64
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• 1996

내부에 사각형 물체가 놓여 있는 사각형수조내 유체의 유동진동수를 선형파이론을 사용하여 산정하였다. 속도포텐셜을 벽체에 의해 발생되는 표면파와 내부물체로 인해 발생되는 반사파, 전달파 및 산란파의 항으로써 표현하였다. 내부물체에 대한 반사율과 전달율은 연속되는 유체영역에서 질량 Flux와 에너지 Flux의 연속조건와 내부물체의 양측면에서의 경계조건을 이용하여 구하였다. 예제해석 결과 유체의 유동진동수는 내부물체가 높고 넓을수록 그리고 물체가 중앙에 가까울수록 감소한다. 내부물체의 크기와 위치의 변화에 의한 유동진동수의 변화는 폭이 수위에 비하여 넓은 수조에서 더욱 민감하다.

• 한국해양공학회지
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• 제32권4호
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• pp.228-236
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• 2018

The performance of a porous swash bulkhead for the reduction of the resonant liquid motion in a swaying rectangular tank was investigated based on the assumption of linear potential theory. The Galerkin method (Porter and Evans, 1995) was used to solve the potential flow model by adding a viscous frictional damping term to the free-surface condition. By comparing the experimental results and the analytical solutions, we verified that the frictional damping coefficient was 0.4. Darcy's law was used to consider the energy dissipation at a porous bulkhead. The tool that was developed with a built-in frictional damping coefficient of 0.4 was confirmed by small-scale experiments. Using this tool, the free-surface elevation, hydrodynamic force (added mass, damping coefficient) on a wall, and the horizontal load on a bulkhead were assessed for various combinations of porosity and submergence depth. It was found that the vertical porous bulkhead can suppress sloshing motions significantly when properly designed and by selecting the appropriate porosity(${\approx}0.1$) and submergence depth.

• 국제초고층학회논문집
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• 제10권2호
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• pp.93-97
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• 2021

Supplementary damping systems, such as tuned mass dampers (TMDs) and tuned sloshing dampers (TSDs) - also known as tuned liquid dampers (TLDs) - have been successfully employed to reduce building motion during wind events. A design of a damping system consisting of a TMD and two TSDs performing in unison has been developed for a tall building in Taiwan to reduce wind-induced motion. The architecturally exposed TMD will also be featured as a tourist attraction. The dual-purpose TSD tanks will perform as fire suppression water storage tanks. Linearized equivalent mechanical TSD and TMD models are coupled to the structure to simulate the multi-degree of freedom system response. Frequency response curves for the structure with and without the damping system are created to evaluate the performance of the damping system. The performance of the combined TMD-TSD system is evaluated against a conventional TMD system by computing the effective damping produced by each system. The proposed system is found to have superior performance in acceleration reduction. The combined TMD-TSD system is an effective and affordable means to reduce the wind-induced resonant response of tall buildings.

• 한국산업융합학회 논문집
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• 제26권1호
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• pp.35-46
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• 2023

A model test is performed to measure the sloshing impact pressure in the liquid tank. A preprocessing is performed to learn the model test results applied with various environmental conditions. In this study, we propose a method for generating data similar to the total pressure data using Generative Adversarial Networks. In addition, after approximating the generated result to the three parameter Weibull distribution, the difference of the three parameters was compared through the RMSE and SMAPE calculation results. As a result, the distribution of the generated data showed similar results to the total pressure data distribution.

• Coupled systems mechanics
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• 제2권4호
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• pp.303-327
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• 2013

The coupled free vibration of flexible structures and on-board liquid in zero gravity space was analyzed, considering the spacecraft main body as a rigid mass, the flexible appendages as two elastic beams, and the on-board liquid as a "spring-mass" system. Using the Lagrangians of a rigid mass (spacecraft main body), "spring-mass" (liquid), and two beams (flexible appendages), as well as assuming symmetric motion of the system, we obtained the frequency equations of the coupled system by applying Rayleigh-Ritz method. Solving these frequency equations, which are governed by three system parameters, as an eigenvalue problem, we obtained the coupled natural frequencies and vibration modes. We define the parameter for evaluating the magnitudes of coupled motions of the added mass (liquid) and beam (appendages). It was found that when varying one system parameter, the frequency curves veer, vibration modes exchange, and the significant coupling occurs not in the region closest to the two frequency curves but in the two regions separate from that region.