• Title/Summary/Keyword: 유탄성 해석

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Nonlinear Hydroelastic Analysis Using a Time-domain Strip Theory m Regular Waves (규칙파중 시간영역 스트립이론을 이용한 비선형 유탄성 해석)

  • CHO IL-HYOUNG;HAN SUNG-KON;KWON SEUNG-MIN
    • Journal of Ocean Engineering and Technology
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    • v.19 no.4 s.65
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    • pp.1-8
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    • 2005
  • A nonlinear time-domain strip theory for vertical wave loads and ship responses is to be investigated. The hydrodynamic memory effect is approximated by a higher order differential equation without convolution. The ship is modeled as a non-uniform Timoshenko beam. Numerical calculations are presented for the S175 Containership translating with the forward speed in regular waves. The approach described in this paper can be used in evaluating ship motions and wave loads in extreme wave conditions and validating nonlinear phenomena in ship design.

Development of a Design Chart for the Initial Design Stage of Very Large Floating Structures (초대형 부유식 해상구조물의 초기 설계를 위한 설계차트 개발)

  • Zi, Goangseup;Kim, Jin Gyun;Lee, Seung Oh;Lee, Phill-Seung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.3B
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    • pp.315-324
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    • 2010
  • We developed a design chart for very large floating structures through intensive hydroelastic analysis. Using this chart, one can predict the hydroelastic response of very large floating structures preliminarily at design stage without the cost-demanding hydroelastic analysis. This paper presents two new design charts based on the theory of VLFS. The purpose of the first design chart is to determine RAOs of the maximum longitudinal stress of VLFS considering properties of waves and structures. The design chart I can be applied to any sizes of VLFS in same aspect ratios and dimensionless stiffness parameters. The second design chart is developed to take into account the actual wave condition by using the Bretschneider spectrum with Beaufort sea state.

Study on Hydroelastic Analysis of Floating Plate Structures (부유식 평판구조물의 유탄성해석 기술에 관한 연구)

  • Kim, Jin-Gyun;Kim, Ki-Tae;Lee, Phill-Seung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2011.04a
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    • pp.209-212
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    • 2011
  • 본 논문에서는 평판(plate) 형태를 갖는 부유식 해상구조물의 유탄성해석에 관한 연구를 수행하였다. 유체력 산정을 위해 포텐셜을 입사, 방사, 산란으로 구분하여 계산하였던 기존의 방법 대신 전체 포텐셜을 직접 계산하는 방법을 사용하여 최근의 경향을 반영하였다. 선형 유탄성해석의 특성을 고려하여 해석시간을 감소시키기 위해 일반적으로 사용되고 있는 주파수 영역에서의 해석 기법을 적용하였다. 구조체의 모델링에 소요되는 요소수를 줄이고, 휨 변형 시 전단변형률에 의한 잠김현상을 해소하기 위해 MITC 기법을 적용한 평판 유한요소를 사용하였으며, 3차원 Green 함수법을 적용해 유체력을 산정하였다.

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Hydroelastic Responses of Floating Structure by Modeling Dimensions (부유구조물의 모델링 차원에 따른 유탄성 응답)

  • Hong, Sanghyun;Hwang, Woongik;Lee, Jong Seh
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.3
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    • pp.285-292
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    • 2016
  • In this study, FE-BE direct coupling methods of 1D and 2D problems are considered for the pontoon-type floating structure and the difference of the modeling dimensions is investigated for the hydroelastic response. The modeling dimensions are defined as the 1D problem consisting 1D beam-2D fluid coupling and the 2D problem consisting 2D plate-3D fluid coupling with zero-draft assumption. For case studies, hydroelastic responses of the 1D Problem are compared to those of the 2D Problem for a wide range of aspect ratio and regular waves. It is shown that the effects of the elastic behavior are increased by decreasing the incident wavelength, whereas the effects of the rigid behavior are increased by increasing the incident wavelength. In 2D problem, the incident wave angle can be considered, and slightly more accurate results can be obtained, but the computational efficiency is lower. On the other hand, in 1D problem with plate-strip condition, the incident wave angle cannot be considered, but when the aspect ratio is large, the overall responses can be analyzed through a simplified model, and the computational efficiency can be improved.

A Visualization System of Very Large Floating Structure Using Processing of Hydro-elastic Analysis Data (유탄성 해석데이터 처리를 통한 초대형 해상구조물의 가상 목업 가시화 기술 개발)

  • Cha, Moohyun;Park, Seongwhan
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.11a
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    • pp.773-774
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    • 2010
  • 본 연구에서는 초대형 부유식 해상 구조물(Very Large Floating Structure) 및 상부 구조물의 동적거동을 실시간 그래픽환경에서 가상 목업을 이용해 가시화하였다. 구조물 자체의 탄성 변형이 고려된 유탄성 응답해석 결과 데이터를 분석하고, 이를 실시간 가시화 시스템에 적용하기 위한 데이터 처리 방법을 소개하였으며, 3 차원 환경에서의 VLFS 및 해양파 가시화 결과와, VLFS 및 상부구조물 거동의 연동 결과를 소개하였다.

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Study on Hydroelastic Analysis of LNGC Cargo by Global-Local Analysis Technique (전역-국부 해석기법에 의한 LNG 운반선 화물창의 유탄성 해석에 관한 연구)

  • Park, Seong-Woo;Cho, Jin-Rae
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.1
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    • pp.83-92
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    • 2007
  • There are many numerical methods to solve large-scale fluid-structure interaction(FSI) problems. However, these methods require very fine mesh to achieve the reasonable numerical accuracy and stability due to the concentrated and volatile hydrodynamic pressure caused by the liquid sloshing. Consequently, the numerical analysis targeting for the long-period time response with the desired numerical accuracy Is very highly time-consuming. The aim of this paper is to suggest a new method to analyze the hydroelastic behavior of the LNGC containment by using the global-local numerical approach. The reliability of the presented method is firstly examined, and then its efficiency is demonstrated by presenting that the long-period local responses of the LNGC containment are obtained with relatively short CPU time.

An Analysis of the Hydroelastic Response of Large Floating Structures in Oblique Waves (사파중에 놓인 거대 부유체의 응답에 대한 유탄성 해석)

  • In-H. Sim;Jae-D. Yoon;Hang-S. Choi
    • Journal of the Society of Naval Architects of Korea
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    • v.36 no.3
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    • pp.83-92
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    • 1999
  • In this paper, the fluid-structure interaction of large floating structures has been rigorously analyzed and the shear effect on the structural deformation has been investigated in oblique waves. A constant panel method(CPM) based on the Green function method is implemented for computing the hydrodynamic pressure, while a finite element method(FEM) is applied for the structural response based on the Mindlin plate theory with including shear deformation. In order to validate the method, we compared numerical results with experimental ones of Mega Float carried out by Yago & Endo in head waves. General behavior shows good agreement but the local displacement at the ends is slightly different. The numerical results show that the radiation pressure due to the fluid-structure interaction is locally larger than that of wave excitation and mooring devices greatly reduce the response. It is observed that the shear effects among the total deformation constitutes about 4% in the case of Mega Float in oblique waves.

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부유구조물 파랑응답 해석

  • Hong, Sa-Yeong;Hong, Seop;Kim, Byeong-Hyeon
    • Bulletin of the Society of Naval Architects of Korea
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    • v.33 no.4
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    • pp.13-20
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    • 1996
  • 해양공간 활용을 위해 예상되는 부유식 해양구조물은 단위구조들이 결합된 형태의 초대형 구조물로서 단위 구조물간의 탄성변형 문제가 매우 중요시되고 있으며 이에 따라 단위구조물간의 상호작용이 고려된 유체력 산출과 탄성응답이 고려된 해석법의 개발이 전세게적으로 활발히 이루어지고 있다. 독립 부유구조물 자체의 크기가 대형화될 때 발생하는 탄성 변형 또한 구조 해석 및 진동관점에서 중요한 고려사항이며, 이는 조선공학분야에서 유탄성 해석기법에 바탕을 두고 연구가 활발히 진행중이다. 본 고에서는 부유구조물의 설계에 있어 핵심기술중 하나인 파랑응답 해석기술의 현황에 대해 살펴보고 현재 한국기계연구원에서 수행중인 국책연구개발사업 "해양공간이용 대형 복합플랜트 개발"의 세부과제인 "부유구조물 파랑응답 해석기법 개발"의 추진내용에 대해 환경 하중/응답해석기술, 계류시스템 설계/해석기술, 유탄성응답 해석기술로 나누어 소개하고자 한다. 해석기술로 나누어 소개하고자 한다.

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