• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.368-372
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• 2008

Habitability is one of the most important points when a passenger ship is cruising. In particular, anti-vibration design should be considered preferentially to offer passenger a comfort cabin and leisure space. But, a passenger ship is different from a general commercial ship in the view point of the structural arrangement. It is restricted within narrow limits to reinforce wide panels and local structures of a passenger ship because of its interior design. Moreover, the allowable vibratory limits for a passenger ship are much lower than those of a commercial ship. In this study are introduced the procedure of the vibration analysis, the structural improvement method for prevention of vibration and the results of vibration measurement during exciter test and sea trials.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.8
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.81-84
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• 2005

A passenger ship has some differences compared with a general commercial ship from the viewpoint of the structural arrangement. It is difficult to reinforce wide panels and local structures of a passenger ship because of its interior design when they have vibration problems. Moreover, the allowable vibratory limit for a passenger ship is much lower than that of a commercial ship. In this study, it is introduced that the procedure of the vibration analysis and the structural improvement for prevention of vibration with consideration of interior design for the Atrium stairway, one of the local structure installed in public space.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.135-140
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• 2010

Vibration on the ship was generated mainly by main engine and propeller. The vibration which is generated from the ship has an effect on durability of ship's machinery and it also has an evil influence on the working conditions for crew. In this research, vibration measurement system to measure ship's vibration was built and vibration signals using acceleration sensors were measured from an accomodation space of training ship. An evaluation of vibration with regard to habitability was also discussed and the evaluation process followed the guidelines ISO6954:2000E.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.3
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• pp.249-258
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• 2005

Recently, the vibration reduction at a local structure such as compass deck has been continuously requested by ship owner and shipbuilder. Because crews are afflicted with vibration, severe vibration problems even bring about a damage of structure. This study conducted to get an optimized stiffener size of compass deck to reduce the vibration level and decrease the weight of structure in ship. NASTRAN external call type optimization software (OptShip) which makes use of NASTRAN as a solver is used as an optimization tool. The results indicate that the optimum design is promising for real applications.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.5
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• pp.528-535
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• 2016

The vibration of a ship gives a significant effect on the noise radiated into the water. This paper focused on the vibration of ship hull due to the sub-generator located on the deck in the anchored condition. The contributions of the transfer paths between sub-generator and ship hull were analyzed using the TPA and the OTPA method. While the sub-generator was operation and the main engine was turned off, the vibrations were measured simultaneously at the 38 locations of the ship and the one hydrophone was arranged to measure the underwater radiated noise at the overside ship. The results of the transfer path by applying TPA and OTPA were compared and discussed. As a result of these methods, the top of stovepipe and valve are contributive. Reinforcing these structures is the most effective to reduce the vibration of ship hull.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.772-778
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• 2011

ISO6954:2000 (Mechanical vibration - Guidelines for the measurement, reporting and evaluation of vibration with regard to habitability on passenger and merchant ships) has taken effect as the governing body for vibration regarding habitability due to ship vibration. However, ISO6954:2000, when compared ISO6954:1984 (the first draft of ISO6954), needs to clear some deficiencies concerning convenience and reliability during field applications. In this paper, ISO6954:1984 and 2000 are evaluated on their suggested assessment method of ship's vibration in the future.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.672-676
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• 2003

Recently, the importance of ship vibration is emerging due to the large scaling, high speed and lightning of ship. For pleasantness in a cabin, shipbuilders ask for strict vibration criteria and the degree of vibration level at a deckhouse became an important condition for taking order from customers. This study conducted optimum design to attenuate vibration level of a deckhouse to solve above problems. New method was implemented, that is NASTRAN external call type independence optimization method. The merit of this method is global searching after setting various object functions and design variables. The global optimization algorithm used here is R-Tabu search method, which has fast converging time and searching various size domains. By modeling similar type to ship structure, validity of the suggested method was investigated.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.443-448
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• 2014

Recently, car-ferry passenger ships of navigating the coast area in the inside of our country are on an increasing trend of main engine power and the height of upper structure, which is increased to ship's speed and loading of large vehicles. The most ship with high-speed main engine is happened to excessive vibration by propeller induced excitation force on account of connecting the vibration of hull's girder and the upper structure by decreasing the shear stiffness and natural frequency for increasing the height of passenger deck. In this paper, By exchanging the propeller of alteration the number of blades, it could be keep to ship's speed and it's decreased the vibration of hull part that is located passenger deck on the upper deck, which is identified by countermeasure of protection against vibration to procure the safety ship's navigation through measuring the vibration of hull structure.