• Journal of Mechanical Science and Technology
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• 제19권11호
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• pp.2061-2067
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• 2005

In this study, we focus on the submerged plate built into the Very Large Floating Structure with the partial openings of Sm long, which enables the reverse flow of incident wave to generate the wave breaking. The purpose of this study is to investigate the characteristics of wave exciting forces acting on the submerged plate and the fore part of VLFS. Firstly, we have carried out the extensive experiments to understand the characteristics of the wave exciting forces. Then we have performed the numerical simulations by applying the Marker and Cell method (MAC method) and compared with the experimental results. We discuss the validity of MAC method and the effects of the submerged plate on the motion of VLFS. As a result, we get the conclusion that the submerged plate is useful for reducing the wave exciting forces acting on the structure behind the submerged plate.

• 대한조선학회논문집
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• 제38권1호
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• pp.72-85
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• 2001

선박 판부재를 대상으로 중요한 하중경우의 하나인 양축방향 면내하중을 작용시키면서 이중판의 폭, 길이, 두께 및 주판(main plate) 부식 영향 등의 각종 파라메타 영향에 따른 이중판의 정적 강도평가를 주판의 접촉효과를 고려한 탄소성 대변형 비선형 시리즈 구조해석을 수행하였으며 이들 해석 결과로부터 각 파라메타의 변화에 따른 강성과 강도 특성을 분석하였다. 또한 이중판의 보강 효과가 최소한 새판으로 치환 보수한 평판 강도 수준으로 설계되어야 하므로 이를 손쉽게 파악할 수 있게 이중판으로 보강된 판부재를 등가 평판 두께로 환산할 수 있는 간이 평가식을 개발하였다. 이 개발식을 이용하여 각 이중판 설계의 영향인자 변화에 따른 등가 평판두께의 증감 정도를 파악하고 이로부터 적어도 새판으로 보수한 평판강도에 달할 수 있게 양축방향 면내 압축하중을 받는 이중판의 설계지침을 제시하였다. 마지막으로, 개발된 등가 평판 도출식은 고정밀 좌굴강도 평가식과 서로 일정한 상관관계가 있음을 확인하고 관계식을 정립하였다. 이 관계식을 각 경우별로 축적하여 앞으로 일일이 구조해석을 수행하지 않고도 설계된 이중판 강도를 등가 평판두께로 제시할 수 있는 간이 추정식의 개발에 이용될 수 있을 것으로 사료된다.

• 대한조선학회논문집
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• 제37권4호
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• pp.92-105
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• 2000

세장한 선박 판부재를 대상으로 가장 중요한 하중인 종방향 면내하중을 작용시키면서 이중판의 폭, 길이, 두께 및 주판(main plate) 부식 영향 등의 각종 파라메타 영향에 따른 이중판의 정적 강도평가를 주판의 접촉효과를 고려한 탄소성 대변형 비선형 시리즈 구조해석을 수행하였으며 이들 해석 결과로부터 각 파라메타의 변화에 따른 강성과 강도 특성을 분석하였다. 또한 이중판의 보강 효과가 최소한 새판으로 치환 보수한 평판 강도 수준으로 설계되어야 하므로 이를 손쉽게 파악할 수 있게 이중판으로 보강된 판부재를 등가 평판 두께로 환산할 수 있는 간이 평가식을 개발하였다. 이 개발식을 이용하여 각 이중판 설계의 영향인자 변화에 따른 등가 평판두께의 증감 정도를 파악하고 이로부터 적어도 새판으로 보수한 평판강도에 달할 수 있게 길이방향 일축 면내 압축하중을 받는 세장한 이중판의 설계지침을 제시하였다. 마지막으로, 개발된 등가 평판 도출식은 고정밀 좌굴강도 평가식과 서로 일정한 상관관계가 있음을 확인하고 관계식을 정립하였다. 이 관계식을 각 경우별로 축적하여 앞으로 일일이 구조해석을 수행하지 않고도 설계된 이중판 강도를 등가 평판두께로 제시할 수 있는 간이 추정식의 개발에 이용될 수 있을 것으로 사료된다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.497-500
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• 2007

Data structure was designed not only to estimate LCC but also to analyze time-variant reliability index of plate girder bridges. Information model for data structure was categorized into cost information, cost variable information, user cost information, and reliability analysis information according to the characteristic of data. EXPRESS language of STEP was adopted to describe the data structure for the electronic representation of LCC information. The suitability of the developed data structure was verified by estimating LCC and analyzing time-variant reliability index of a plate girder bridge considering corrosion on the basis of the constructed test database.

• 한국농촌건축학회논문집
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• 제16권2호
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• pp.1-8
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• 2014

In the past, Korea was classified as a region not affected by earthquakes. However, recent increase of earthquakes has forced to strengthen standards of earthquake resistant designs of structures to minimize seismic damage. In addition, it was thought that masonry infill walls in buildings are only acting as partitions, so these walls are not considered in analyzing building structures. But it was found that when seismic loads are applied to a structure with masonry infill walls, the walls affect the structure. Accordingly, this study conducted nonlinear static analyses for a structure constructed before applying earthquake resistant designs in two cases: when considering masonry walls and when not. The result showed that the seismic performance of the structure is insufficient. Thus, the structural resistance of the structure was also studied in two cases: when reinforcing with steel plate braces and when using carbon fiber braces. In the two cases reinforcing two different stiffeners, it was appeared that the behaviors of the structure were similar, though the cross-section area of a carbon fiber brace used to reinforcing the structure is only 12.6% of a steel plate brace, and its weight is only 2.8%. Thus, the reinforcing effect of the thin, light-weighted carbon fiber brace is much larger than that of the steel plate brace, when considering usability and constructability of both materials.

• Steel and Composite Structures
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• 제34권5호
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• pp.733-742
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• 2020

Vibration analysis in nanocomposite plate with smart layer is studied in this article. The plate is reinforced by carbon nanotubes where the Mori-Tanaka law is utilized for obtaining the effective characteristic of structure assuming agglomeration effects. The nanocomposite plate is located in elastic medium which is simulated by spring element. The motion equations are derived based on first order shear deformation theory and Hamilton's principle. Utilizing Navier method, the frequency of the structure is calculated and the effects of applied voltage, volume percent and agglomeration of Carbon nanotubes, elastic medium and geometrical parameters of structure are shown on the frequency of system. Results indicate that with applying negative voltage, the frequency of structure is increased. In addition, the agglomeration of carbon nanotubes reduces the frequency of the nanocomposite plate.

• 한국항해학회지
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• 제25권4호
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• pp.461-469
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• 2001

The purpose of this paper is the optimum modification of dynamic characteristics of stiffened plate structure including the number of stiffener. This paper shows the optimum structural modification method by dynamic sensitivity analysis and quasi-least squares method and considers it's validity. In the method of the optimization, finite element method, sensitivity analysis and optimum structural modification method are used. The change of natural frequency and total weight are made to be an objective function. Thickness of plate, the number of stiffener and cross section moment of stiffener become a design variable. The dynamic characteristics of stiffened plate structure is analyzed using finite element method. Next, rate of change of dynamic characteristics by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using optimum structural modification method. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure including the number of stiffener.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.207-208
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• 2006

Sandwich structures, which are composed of a thick core between two faces, are commonly used in many engineering applications because they combine high stiffness and strength with low weight. In this paper, we have investigated the buckling protection of an inner structure plate and the useful corrugated configuration for contact, and the fabrication method of the inner structure plate for large area using the continuous molding process. Also, we have guaranteed the accuracy of the molding process through the micro corrugated mold fabrication and analyzed aspect properties of the inner structure plate fabricated for a large area using the partial mold process.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.529-534
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• 2002

The receptance method was applied for the analysis of a cylindrical shell with a curvaturated plate attached at the top of the shell. The boundary conditions of the shell considered here were clamped at the bottom and free at the top of the shell. Before the analysis of the shell/plate combined structure, the natural frequencies of the plate and the shell were calculated separately and then they were used in the calculation of the frequencies of the combined structure by the receptance method. The frequency equation of the combined structure was derived from the continuity condition at the junction of the shell and the plate. The frequencies for various curvature factors of the plate were presented and compared with those from ANSYS to show its validity of the present method.

• 소음진동
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• 제7권4호
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• pp.589-596
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• 1997

A energy equation for a thin plate and surrounding fluid is derived. The equation essentially determines the relation between internal loss of thin plate, energy of acoustic radiation, and structure intensity. We attempted to use this relation to measure internal loss of thin plate. The significance of this approach is that internal loss at any point of a thin plate can be measured. The quality of this measure is dicated by the accuracy of associated measurement systems such as structure and acoustic intensity measurements. A strain gauge bridge system has been developed to measure structure intensity of thin plate. Its performance is tested by experiments.