• 한국소음진동공학회논문집
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• 제21권8호
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• pp.761-767
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• 2011

Free and forced vibration analysis of the global ship structure using the 3-dimensional finite element(FE) method requires not only the specialized knowledge such as ship structure interacted with fluid, damping and various excitations due to propulsion system but also time-consuming manual tasks in FE modeling, analysis and response evaluation. As a result, the quality of the vibration analysis highly depends on engineer's expertise and experience. In this study, a framework system to improve the efficiency of global ship vibration analysis is introduced. The system promising the utilization of MSC/Patran and MSC/Nastran consists of various modules to support data management, FE modeling of ship structure and loading, input deck generation for free and forced vibration analysis, data extraction and evaluation of analysis results, and databases for FE models of marine diesel engines and vibration criteria. The system may be useful for pursuing standardization of uncertain analysis factors as well as reducing time, cost and human dependency in ship vibration analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.779-784
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• 2011

Free and forced vibration analysis of the global ship structure using the 3-dimensional finite element(FE) method requires not only the specialized knowledge such as ship structure interacted with fluid, damping and various excitations due to propulsion system but also time-consuming manual tasks in FE modeling, analysis and response evaluation. As a result, the quality of the vibration analysis highly depends on engineer's expertise and experience. In this study, a framework system to improve the efficiency of global ship vibration analysis is introduced. The system promising the utilization of MSC/Patran and MSC/Nastran consists of various modules to support data management, FE modeling of ship structure and loading, input deck generation for free and forced vibration analysis, data extraction and evaluation of analysis results, and databases for FE models of marine diesel engines and vibration criteria. The system may be useful for pursuing standardization of uncertain analysis factors as well as reducing time, cost and human dependency in ship vibration analysis.

• 대한조선학회논문집
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• 제48권4호
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• pp.368-374
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• 2011

Recently, the ship vibration analysis technique has been well set up by using FEM. The methods considering the hydrodynamic added mass and damping of the fluid surrounding a floating ship have been well developed, so that they can be calculated by using the commercial package FEM programs such as MSC/NASTRAN, ADINA and ANSYS. Especially, MSC/NASTRAN has the functions to consider the fluid in tanks(MFLUID) and to solve the Fluid-Structure Interaction(FSI) problem(DMAP). In this study, the global ship vibration with considering the added mass distributed at the grid points on the wetted shell surface is introduced to. In the new method, the velocity potentials of the fluid surrounding a floating ship are calculated by solving the Lapalce equation using the Boundary Element Method(BEM), and the point mass is obtained by integrating the potentials at the points. Then, the global vibration analyses of the ship structure with distributed added mass on the wetted surface are carried out for an oil/chemical tanker. During the future sea trial, the results will be confirmed by measurement.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.329-330
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• 2008

The 181,000 DWT Bulk Carrier has a different deck house type, which is not typical for previous bulk carriers, to meet the new international rules for bulk carriers. This new deck house has much smaller transverse breadth than the hull's transverse breath, resulting in large levels of the transverse response of the deck house. In addition, the longitudinal response of the funnel showed rather a large magnitude of vibration, which are excited by the ship's main excitations such as the main engine H-moment and the propeller surface forte when the ship operates at the NCR and the MCR speeds In the ballast condition. To solve these issues, the global forced vibration analysis has been performed for the ship and the ship structure has been modified to reduce the vibration level by increasing the girder depth and adjusting the engine room tank arrangement.

• 대한조선학회논문집
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• 제44권3호
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• pp.314-322
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• 2007

In general, the vibration and structural analyses have been carried out by using each finite element model separately because of different size of finite element mesh and different focusing area of each analysis. In some cases, however, it is required to perform both global vibration and structural analyses at the same time using a finite element model for global structural analysis, which asks for a special treatment for a vibration analysis. In this study, a technique to perform a global vibration analysis using a finite element model for a global structural analysis has been developed and its effectiveness has been verified by its application to a whole ship.

• 한국CDE학회논문집
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• 제10권1호
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• pp.61-69
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• 2005

In the global ship structure and vibration analysis, the FE(finite element) analysis model is required in the early design stage before the 3D CAD model is defined. And the analysis model generation process is a time-consuming job and takes much more time than the engineering work itself. In particular, ship structure has too many associated structural members such as stringers, stiffness and girders etc. These structural members should be satisfied as the constraints in analysis modeling. Therefore it is necessary to support generation of analysis model with satisfying these constraints as an automatic manner. For the effective support of the global ship analysis modeling, a method to generate analysis model using initial design information within ship design process, that hull form offset data and compartment data, is developed. In order to easily handle initial design information and FE model information, flexible data structure is proposed. An automatic quadrilateral mesh generation algorithm using initial design information to satisfy the constraints imposed on the ship structure is also proposed. The proposed data structure and mesh generation algorithm are applied for the various type of vessels for the usability test. Through this test, we have verified the stability and usefulness of this system including mesh generation algorithm.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.693-694
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• 2012

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.695-696
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• 2012

• 소음진동
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• 제9권1호
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• pp.206-213
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• 1999

선박의 보-유추 진동해석에 있어 2차원 부가수질량의 3차원 효과를 고려하기 위해서 3차원 수정계수(J-factor)를 계산해야 하는데 광폭선의 경우에는 J-factor의 계산이 부정확하고 번거롭다. 이 논문에서는 이를 개선하기 위해 새로운 선박의 보-유추 접수진동해석 방법을 소개하였다. 이 방법은 선박에 접수된 유체에 대해 BEM 기법을 이용하여 3차원 유체력을 직접 계산하고 이를 일정 간격으로 나눈 각 스트립에 집중질량으로 평가한 후에 선체의 보모델과 결합하여 보-유추 진동해석을 수행하는 방법이다. 오픈탑 컨테이너선의 모델에 대해 기존의 보-유추 진동해석방법과 이 논문에서 제시한 새로운 진동해석방법을 이용하여 진동해석을 수행하고 가진 실험에 의한 진동계측결과와 상호 비교함으로써 새로운 방법의 유용성을 검증하였다.

• 한국소음진동공학회논문집
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• 제27권1호
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• pp.14-19
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• 2017

Fuel oil consumption cost varies depending on every ship operation and this roughly amounts to 70 % of shipping companies' total revenue. As such, efforts towards improved fuel economy are being pursued. An annual 1 % reduction in fuel consumption is perceived to result in saving tens million US dollars on the global fleet operation. One approach is the application of power take-off configurations which are seen to increase fuel oil economy and are suitable for power generation. In this study, the dynamic properties of a shaft generator coupled on a 10S90ME main engine of an 18 600 TEU container vessel is presented. The vibratory torque and angular velocity variation was examined through theoretical analysis and actual vibration measurement. The result of the study suggests a review on existing classification rules for generator design and the lowering of vibratory torque and angular velocity variation guideline.