• 제목/요약/키워드: 케이블 동역학

검색결과 13건 처리시간 0.023초

해양 응용을 위한 케이블 동역학 (Cable Dynamics for Marine Applications -Nonlinearities-)

  • 신현경
    • 한국해양공학회지
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    • 제4권2호
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    • pp.35-40
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    • 1990
  • 해양 산업에서 심해로의 이동은 해양 구조물의 계류 장치의 중요성을 부각시켰고 그에 따른 기본적인 연구로서의 케이블 동력학에 대한 흥미를 일깨웠다. 거친 해상에서 케이블에 형성될 수 있는 큰 동장력과 기하학적 비선형성의 고려는 케이블의 비선형적 거동 해석에 주요 인자가 될 것이다. 또한 매우 큰 동장력 증폭에 의한 음의 큰 동장력은 케이블의 양의 정장력을 초과할 수 있고, 따라서 전체장력은 영 또는 음이 될 수 있다. 비선형 유체 항력을 포함한 모든 비선형성을 갖는 케이블의 이론적 해석 모델을 개발하고, 수치 결과와 기존의 실험 결과를 비교한다.

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다물체 시스템이 이동하는 유연한 케이블의 동역학 해석에 관한 연구 (Dynamic Analysis of a Very Flexible Cable Carrying A Moving Multibody System)

  • 서종휘;정일호;한형석;박태원
    • 한국소음진동공학회논문집
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    • 제14권2호
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    • pp.150-156
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    • 2004
  • In this paper, the dynamic behavior of a very flexible cable due to moving multibody system along its length is presented. The very deformable motion of a cable is presented using absolute nodal coordinate formulation, which is based on the finite element procedures and the general continuum mechanics theory to represent the elastic forces. Formulation for the sliding joint between a very flexible beam and a rigid body is derived. In order to formulate the constraint equations of this joint, a non-generalized coordinate, which has no inertia or forces associated with this coordinate, is used. The modeling of this sliding joint is very important to many mechanical applications such as the ski lifts. cable cars, and pulley systems. A multibody system moves along an elastic cable using this sliding joint. A numerical example is shownusing the developed analysis program for flexible multibody systems that include a large deformable cable.

비선형 동적 거동 해석을 통한 광섬유 케이블의 풀림 성능 예측 연구 (Prediction of the Unwinding Performance of Optical Fiber Cables by Nonlinear Dynamics Analysis)

  • 이재욱;김건우;김형렬;유완석;안득만
    • 대한기계학회논문집A
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    • 제34권3호
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    • pp.347-352
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    • 2010
  • 원격조정이 불가능한 수중운동체를 제어하기 위해서는 선 유도 제어기술이 효과적으로 사용된다. 스풀에 수십 킬로미터의 길이로 감겨있는 광섬유가 풀릴 때, 수중운동체의 거동과 광섬유의 풀림 속도의 차이에 기인한 큰 장력과 장력 변동이 발생할 수 있다. 이로 인해, 광섬유의 복잡한 거동으로 인한 엉킴 또는 절손의 문제가 발생한다. 그러므로 본 논문에서는 빠른 속도로 풀리는 광섬유의 풀림 동역학 해석을 수행하여 광섬유가 풀리는 동안의 비선형 거동 및 장력, 장력변동을 파악함으로써 설계된 스풀의 풀림 성능을 예측하는 방법을 연구하였다.

케이블에 의하여 매달려 있는 현수교 방정식의 발견과 연구의 흐름 (The Bridge Suspended by Cables and the History of Investigation of the Equation Induced from It)

  • 남혜원;최규홍
    • 한국수학사학회지
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    • 제18권2호
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    • pp.107-116
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    • 2005
  • 현수교 방정식은 비선형 동역학 시스템 중 점프가 일어나는 비선형 부분을 갖는 대표적인 예이다. 터코마 내로스(Tacoma Narrows) 현수교의 붕괴 이후 현수교 유사한 조건에 대한 연구 및 현수교의 안정성에 대한 연구가 활발히 진행되었다. 이 논문에서는 현수교 방정식의 모델링과 해의 존재성 및 다중성 연구에 대하여 조사하였다.

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케이블-수중 예인체 시스템의 3차원 비선형 완전 연성해석 (3D Nonlinear Fully Coupled Simulation of Cable and Tow-fish System)

  • 고광수;이은택;안형택
    • 한국해양공학회지
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    • 제30권6호
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    • pp.458-467
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    • 2016
  • In this paper, a strongly coupled method for investigating the interaction between a cable and tow-fish is presented. The nodal position finite element method was utilized to analyze the nonlinear cable dynamics, and 6DOF equations of motion were employed to describe the 3D rigid body motion of the tow-fish. Combining cable and tow-fish systems into a single formulation allowed the two nonlinear systems to be strongly coupled into a unified nonlinear system. This strongly coupled system was numerically integrated in the time domain using a predictor/multi-corrector Newmark algorithm. To demonstrate the validity, efficacy, and applicability of the current approach, two different scenarios (virtual and sea trial) were simulated, and the simulation results were validated using the physical plausibility and the sea trial test.

URI-T, 해저 케이블 매설용 ROV의 선수각 제어 및 실해역 검증 (Heading Control of URI-T, an Underwater Cable Burying ROV: Theory and Sea Trial Verification)

  • 조건래;강형주;이문직;이계홍
    • 한국해양공학회지
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    • 제33권2호
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    • pp.178-188
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    • 2019
  • When burying underwater cables using robots, heading control is one of the key functions for the robots to improve task efficiency. This paper addresses the heading control issue for URI-T, an ROV for underwater construction tasks, including the burial and maintenance of cables or small diameter pipelines. Through modeling and identifying the heading motion of URI-T, the dynamic characteristics and input limitation are analyzed. Based on the identification results, a PD type controller with appropriate input treatment is designed for the heading control of URI-T. The performance of the heading controller was verified in water tank experiments. The field applicability of the proposed controller was also evaluated through the sea trial of URI-T at the East Sea, with a water depth of 500 m.

탄성 대변형 다물체동역학을 위한 슬라이딩조인트 개발 (The Development of a Sliding Joint for Very Flexible Multibody Dynamics)

  • 서종휘;정일호;수기야마;사바나;박태원
    • 대한기계학회논문집A
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    • 제29권8호
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    • pp.1123-1131
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    • 2005
  • In this paper, a formulation for a spatial sliding joint, which a general multibody can move along a very flexible cable, is derived using absolute nodal coordinates and non-generalized coordinate. The large deformable motion of a spatial cable is presented using absolute nodal coordinate formulation, which is based on the finite element procedures and the general continuum mechanics theory to represent the elastic forces. And the non-generalized coordinate, which is neither related to the inertia forces nor external forces, is used to describe an arbitrary position along the centerline of a very flexible cable. In the constraint equation for the sliding joint, since three constraint equations are imposed and one non-generalized coordinate is introduced, one constraint equation is systematically eliminated. Therefore, there are two independent Lagrange multipliers in the final system equations of motion associated with the sliding joint. The development of this sliding joint is important to analyze many mechanical systems such as pulley systems and pantograph/catenary systems for high speed-trains.

강건 절점위치 유한요소법을 이용한 수중 예인 케이블의 비선형 거동해석 (Nonlinear Analysis of Underwater Towed Cable Using Robust Nodal Position Finite Element Method)

  • 이은택;고광수;안형택;김성일;천승용;김정석;이병희
    • 대한조선학회논문집
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    • 제53권5호
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    • pp.388-399
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    • 2016
  • A motion analysis of an underwater towed cable is a complex task due to its nonlinear nature of the problem. The major source of the nonlinearity of the underwater cable analysis is that the motion of the cable involves large rigid-body motion. This large rigid-body motion makes difficult to use standard displacement-based finite element method. In this paper, the authors apply recently developed nodal position-based finite element method which can deal with the geometric nonlinearity due to the large rigid-body motion. In order to enhance the stability of the large-scale nonlinear cable motion simulation, an efficient time-integration scheme is proposed, namely predictor/multi-corrector Newmark scheme. Three different predictors are introduced, and the best predictor in terms of stability and robustness for impulsive cable motion analysis is proposed. As a result, the nonlinear motion of underwater cable is predicted in a very efficient manner compared to the classical finite element of finite difference methods. The efficacy of the method is demonstrated with several test cases, involving static and dynamic motion of a single cable element, and also under water towed cable composed of multiple cable elements.

디지털 카메라를 이용한 구조물의 동특성 추출 (Modal Parameter Extraction Using a Digital Camera)

  • 김병화
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 추계학술대회논문집
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    • pp.61-68
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    • 2008
  • A set of modal parameters of a stay-cable have been extracted from a moving picture captured by a digital camera supported by shaking hands. It is hard to identify the center of targets attached on the cable surface from the blurred cable motion image, because of the high speed motion of cable, low sampling frequency of camera, and the shaking effect of camera. This study proposes a multi-template matching algorithm to resolve such difficulties. In addition, a sensitivity-based system identification algorithm is introduced to extract the natural frequencies and damping ratios from the ambient cable vibration data. Three sets of vibration tests are conducted to examine the validity of the proposed algorithms. The results show that the proposed technique is pretty feasible for extracting modal parameters from the severely shaking motion pictures.

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