• 제목/요약/키워드: Dolphin structure

검색결과 18건 처리시간 0.017초

강관말뚝식 계류돌핀의 수치적 설계최적화 (Numerical Design Optimization of Mooring Dolphin of Steel Pile Type)

  • 이나리;류연선;김정태;서경민;조현만
    • 한국해양공학회지
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    • 제13권3호통권33호
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    • pp.3-11
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    • 1999
  • Optimum design of mooring dolphin is numerically investigated. Design optimization problem of moring dolphin is first formulated. Geometry and cross sections of piles are used as design variables. Design objective is the total weight of steel piles of mooring dolphin, and the constraints of stress, penetration depth, lower and upper bounds on design variables are imposed. Based on the design variable linking and fixing, several class of design variations are sought. For the numerical optimization, both PLBA(Pshenichny - Lim - Belegundu - Arora) program and DNCONF subroutine code in IMSL library are used. For a dolphin structure with 20 steel piles, vertical and inclined, optimum designs for different cases are successfully obtained, which can be applied for the mooring of a very large floating structure.

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불규칙파 중에서 돌핀 계류된 해상공항에 대한 운동 해석 (Motion Analyses for a Very Large Floating Structure with Dolphin Mooring Systems in Irregular Waves)

  • 이호영;신현경;임춘규;강점문;윤명철
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2000년도 추계학술대회 논문집
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    • pp.57-62
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    • 2000
  • The very large flcating structure which am be used for as airport may be as large as several kilomet wide. The first order wave forces as well as wave drift forces are very important forces on such a very large floating In the present studv, the time simulation of motion responses with dolphin-moored VLFS in waves is presented The coeffcients and wave forces involved in the equations are obtained from a three-dimensionul panel method in the frequc The horizontal drift forces and mooring forces for dolphin systems are taken into account. As for numerical example, analyses are carried out for a VLFS in irregular wave condition

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초대형 부유식 구조물의 돌핀-펜더계류시스템에 관한 실험연구 (Experimental Study on a Dolphin-Fender Mooring System for Pontoon-Type Structure)

  • 김진하;조석규;홍사영;김영식
    • 대한조선학회논문집
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    • 제42권1호
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    • pp.43-49
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    • 2005
  • in this paper a dolphin-fender moored pontoon-type floating structure in shallow water depth is studied focusing on mooring force. The pontoon-type floating structure is 500m long, 300m wide. The structure has partially non-uniform drafts of 2.0m and 3.0m. The employed mooring system is a guyed frame type dolphin-fender system. The 1/125 scale model fender system is made of rubber tube to have hi-linear load deflection characteristics. A series of model tests has been conducted focusing on motion and fender force responses in regular and irregular waves at KRISO's ocean engineering basin Non-linear numerical simulation of fender reaction force has been carried out and the results are compared with those of model tests. The simulated rigid body motion and mooring forces also have been compared with the test results.

선박의 충돌로 인한 해양구조물의 거동 해석 (Behaviour Analyses of Ocean Structure Due to Ship Collision)

  • 이호영
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 춘계학술대회 논문집
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    • pp.103-107
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    • 2001
  • When ship claps against the ocean structure sited at shallow water, the time simulation of motion responses of dolphin-moored ocean structure is presented. The equatien of motion based on Cummin's theory of impulse responses are employed, and solved in time domain by using the Newmark $\beta$ method. The added mass and damping coefficients involved in the equations are obtained from a three-dimensional panel method in the frequency domain. The impact forces due to ship collision are modeled as two method, and those are elastic and non-elastic collisions. The mooring forces for dolphin systems of scean structure are considered as linear spring system.

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강관말뚝식 계류돌핀의 수치적 설계최적화 (Numerical Design Optimization of Mooring Dolphin of Steel Pile Type)

  • 이나리;류연선;김정태;서경민
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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    • pp.237-244
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    • 1998
  • Optimum design of mooring dolphin is numerically investigated. Design optimization problem of mooring dolphin is first formulated. Geometry and cross sections of piles are used as design variables. Design objective is the total weight of steel piles of mooring dolphin and the constraints of stress, penetration depth, lower and upper bounds on design variables are imposed. Based on the design variable linking and fixing, several class of design variations are sought. For the numerical optimization, both PLBA( Pshenichny-Lim-Belegundu-Arora) program and DNCONF subroutine code in IMSL library are used. For a dolphin with 20 steel piles, vertical and inclined, optimum designs for different cases are successfully obtained, which can be applied for the mooring of a large floating structure.

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선박의 충돌로 인한 해양구조물의 거동 해석 (Analyses on the Behaviour of Ocean Structure Due to Ship Collision)

  • 이호영;박종환;곽영기
    • 한국해양공학회지
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    • 제15권4호
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    • pp.115-119
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    • 2001
  • The simulation of motion responses of a dolphin-moored ocean structure in shallow water when it cllides with a ship, has been carried out. The equation of motion in the time domain according to Cummin's theory is employed, and solved by making use of the Newmark-${\beta}$ method. The added mass and damping coefficients involved in the equations are abtained from a three-dimensional panel method in the frequency domain. The impact forces due to ship collision are calculated using both the elastic and non-elastic modelings. The mooring forces for dolphin systems of ocean structure are regarded as linear spring forces.

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선박충돌 시 돌핀 구조물의 거동에 대한 원심모형실험 (Centrifugal Test on Behavior of the Dolphin Structure under Ship Collision)

  • 오승탁;배우석;조성민;허열
    • 한국지반환경공학회 논문집
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    • 제12권1호
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    • pp.61-70
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    • 2011
  • 충돌보호공은 해저지반에 깊게 근입되어 있으며 돌핀을 의미하는 상부는 단단한 콘트리트 뚜껑으로 막혀지고 쇄석으로 채워진 원형의 속채움 시트파일의 배열로 구성된다. 본 연구에서는 돌핀의 거동을 규명하기 위해 총 7회의 준정적실험과 11회의 동적 원심모형실험을 수행하였다. 주요한 실험적 결과는 다음과 같다. 우선, 준정적실험의 실험적인 힘-변위 결과는 채움재 강성과 관련된 채움 밀도의 변화로부터 구조물의 초기 강성에 대한 영향을 보여준다. 그리고 동일한 변위에서의 에너지 소산을 비교해보면 더 조밀한 채움에서 직경 20m 돌핀은 16%, 직경 30m 돌핀은 23% 정도 소산율이 증가하는 것으로 나타났다. 30m 직경의 돌핀이 더 큰 민감도를 갖는 것은 채움재의 변형률이 에너지소산에 대해 보다 크게 기여하기 때문이다. 동 정적 충돌실험결과, 일반적으로 동적 응답이 준정적 응답보다 26~58%까지 크고 더 작은 변위에서 에너지 소산이 발생되고 있음을 알 수 있다. 따라서 돌핀 구조물의 거동예측 시 준정적 응답특성을 사용하는 것이 보수적이라는 것을 알 수 있으며, 하부충돌 시 돌핀 저항력은 상부충돌 시와 동일하거나 더 우세한 것으로 나타났다.

지반의 강성특성을 고려한 지반-돌핀구조계의 동적해석 (Dynamic Analysis of Mooring Dolphin System Considering Soil Properties)

  • 이진학;오세붕;윤정방;홍섭;김진하
    • 한국해양공학회지
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    • 제12권3호통권29호
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    • pp.19-30
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    • 1998
  • In this paper, the dynamic analysis of a dolphin system for mooring a floating structure such as barge mounted plant is studied. The characteristics of the soil-pile system are simplified by a set of equivalent spring elements at the mudline. To evaluate the equivalent spring constants, the finite difference method is used. Since the characteristics of the soil-pile system are nonlinear in case of soft foundation, the nonlinear dynamic analysis technique is needed. The Newmark $beta$ method incorporating the modified Newton-Raphson method(initial stiffness method) is used. A numerical analysis is performed on two mooring dolphin systems on soft foundation and rock foundation. In case of the rock foundation, the characteristics are found to be nearly linear, so the linear dynamic analysis may be sufficient to consider the foundation effect. But in case of soft foundation, the non-linearity of the foundation appears to be very signigicant, so the nonlinear dynamic analysis si needed.

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Optimum design of steel frame structures by a modified dolphin echolocation algorithm

  • Gholizadeh, Saeed;Poorhoseini, Hamed
    • Structural Engineering and Mechanics
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    • 제55권3호
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    • pp.535-554
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    • 2015
  • Dolphin echolocation (DE) optimization algorithm is a recently developed meta-heuristic in which echolocation behavior of Dolphins is utilized for seeking a design space. The computational performance of meta-heuristic algorithms is highly dependent to its internal parameters. But the computational time of adjusting these parameters is usually extensive. The DE is an efficient optimization algorithm as it includes few internal parameters compared with other meta-heuristics. In the present paper a modified Dolphin echolocation (MDE) algorithm is proposed for optimization of steel frame structures. In the MDE the step locations are determined using one-dimensional chaotic maps and this improves the convergence behavior of the algorithm. The effectiveness of the proposed MDE algorithm is illustrated in three benchmark steel frame optimization test examples. Results demonstrate the efficiency of the proposed MDE algorithm in finding better solutions compared to standard DE and other existing algorithms.

Dolphin Echolocation Optimization: Continuous search space

  • Kaveh, A.;Farhoudi, N.
    • Advances in Computational Design
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    • 제1권2호
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    • pp.175-194
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    • 2016
  • Nature has provided inspiration for most of the man-made technologies. Scientists believe that dolphins are the second to humans in smartness and intelligence. Echolocation is the biological sonar used by dolphins for navigation and hunting in various environments. This ability of dolphins is mimicked in this paper to develop a new optimization method. Dolphin Echolocation Optimization (DEO) is an optimization method based on dolphin's approach for hunting food and exploration of environment. DEO has already been developed for discrete optimization search space and here it is extended to continuous search space. DEO has simple rules and is adjustable for predetermined computational cost. DEO provides the optimum results and leads to alternative optimality curves suitable for the problem. This algorithm has a few parameters and it is applicable to a wide range of problems like other metaheuristic algorithms. In the present work, the efficiency of this approach is demonstrated using standard benchmark problems.