• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 제 23회 정기총회 및 추계학술발표회
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• pp.27-36
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• 1998

This paper presents a brief outline of dynamic stability of damaged ship in rough, beam wind and waves. The one degree-of-freedom, linear roll equation is adopted with the effects of damage fluid and external forces, but without the effect of sloshing. We evaluate the dynamic stability in terms of capizing probability based on energy balance mechanics and risk analysis , the method of which was proposed by Umeda [2] to the high speed crafts. As a result, we can predict the dynamic stability quantitatively according to sea state , operating and damage conditions.

• 대한조선학회논문집
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• 제50권3호
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• pp.175-181
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• 2013

This paper presents a simulation for passenger ship evacuation considering the inclination of a ship. In order to describe a passenger's behavior in an evacuation situation, a passenger is modeled as a rigid body which translates in the horizontal plane and rotates along the vertical axis. The position and rotation angle of a passenger are calculated by solving the dynamic equations of motions at each time step. To calculate inclined angle of damaged ship, static equilibrium equations of damaged ship are derived using "added weight method". Using these equations, physical external forces due to the inclination of a ship act on the body of each passenger. The crowd behavior of the passenger is considered as the flock behavior, a form of collective behavior of a large number of interacting passengers with a common group objective. Passengers can also avoid an obstacle due to penalty forces acting on their body. With the passenger model and forces acting on its body, the test problems in International Maritime Organization, Maritime Safety Committee/Circulation 1238(IMO MSC/Circ.1238) are implemented and the effects of ship's inclination on the evacuation time are confirmed.

• 대한조선학회논문집
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• 제42권5호
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• pp.435-447
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• 2005

The 24th ITTC Specialists Committee on Stability in Waves is conducting an international benchmark study where numerical methods for the calculation of ship motion in damaged condition are compared on the basis of specified tests in order to assess the present state of the art in this field. The study is finished and some results are presented in this paper providing an initial insight into the status of damage models and numerical methods and a collective assessment of their performance. The preliminary analysis has shown that current methods are satisfactory, capturing the fundamental physical performance of damaged ships in specified conditions.

• 대한조선학회논문집
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• 제56권1호
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• pp.34-46
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• 2019

This paper provides the numerical results for the self-propulsion performance in waves of a car ferry vessel with damage in one of its twin-screw propulsion systems without flooding the engine room. The numerical simulations were carried out according to the Safe Return to Port (SRtP) regulation made by the Lloyd's register, where the regulation requires that damaged passenger ships should have an ability to return to port with a speed of 6 knots in a Beaufort 8 sea condition. For the validation of the present numerical analysis study, the resistance performance and the self-propulsion performance of the car ferry in intact and damaged conditions in calm water were calculated, which showed a satisfactory agreement with the model test results of Korea Research Institute of Ship and Ocean engineering (KRISO). Finally, the numerical simulation of self-propulsion performance in waves of the damaged car ferry ship was carried out for a normal sea state and for a Beaufort 8 sea state, respectively. The estimated average Brake Horse Power (BHP) for keeping the damaged car ferry ship advancing at a speed of 6 knots in a Beaufort 8 sea state reached about 47% of BHP at MCR condition or about 56% of BHP at NCR condition of the engine determined at the design state. In conclusion, it can be noted that the engine power of the damaged car ferry ship in single propulsion condition is sufficient to satisfy the SRtP requirement.

• 시스템엔지니어링학술지
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• 제16권2호
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• pp.110-117
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• 2020

In this paper, we estimated the straight line stability by performing a 3 degree of freedom spiral test simulation of a intact/damaged surface combatant using the hydrodynamic coefficient obtained through the PMM(Planar motion mechanism) test based on system engineering process. A model ship was ONR Tumblehome and damaged compartment was set on the starboard bow. As a result of conducting a spiral test simulation based on the experimental results of J.Ha (2018), the asymmetric straight line stability due to the damaged compartment was confirmed. In the case of a ship in which the starboard bow was damaged, it was confirmed that it had the characteristic to deflect to the left when going straight. Also, when estimating the straight line stability of a both port and starboard asymmetric surface combatant, a separated equation of motion model that sees the port and starboard as different ships seems suitable.

• 한국해양공학회지
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• 제25권3호
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• pp.1-10
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• 2011

This paper estimates the residual longitudinal strength of a damaged double hull VLCC (Very Large Crude Carrier) under combined vertical and horizontal bending moments using Smith's method. The damage estimated in this study occurred due to collision or grounding accidents. The effects of the randomness of the yield stress, plate thickness, extent of damage, and the combination of these three parameters on the ultimate hull girder strength were investigated. Random variables were generated by a Monte Carlo simulation and applied to the double hull VLCC described by the ISSC (International Ship and Offshore Structures Congress) 2000 report.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권2호
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• pp.236-244
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• 2014

Although a safety assessment of damaged ships, which considers environmental conditions such as waves and wind, is important in both the design and operation phases of ships, in Korea, rules or guidelines to conduct such assessments are not yet developed. However, NATO and European maritime societies have developed guidelines for a safety assessment. Therefore, it is required to develop rules or guidelines for safety assessments such as the Naval Ship Code (NSC) of NATO. Before the safety assessment of a damaged ship can be performed, the available damage scenarios must be developed and the safety assessment criteria must be established. In this paper, the parameters related to damage by accidents are identified and categorized when developing damage scenarios. The need for damage safety assessment criteria is discussed, and an example is presented. In addition, a concept and specifications for the DB-based supporting system, which is used in the operation phases, are proposed.

• 대한조선학회논문집
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• 제31권3호
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• pp.119-128
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• 1994

기관실 상갑판 특히 거주구 외부의 상갑판 판부재는 외적인 수직하중이 거의 작용하지 않음에도 불구하고 건조중인 대형선박에서 갑판에 널리 대처짐 현상이 발생할 때가 있는 반면에 수직하중이 작용하는 거주구 내부의 기관실 상갑판은 처짐발생 크기 및 분포정도가 미미한, 규명하기 어려운 현상들이 나타나고 있다. 따라서, 본 연구에서는 3차원 구조해석으로부터 얻은 거주구 및 자중에 의한 정적하중의 영향, 손상보고에 따라 계측된 처짐량 자료 및 분포상황, 초기처짐의 크기 및 형상, 용접잔류응력, 면내하중 성분들을 대상으로 비선형 시리즈 해석을 수행하고, 이로부터 판부재에 발생하는 최대처짐 추정식을 제시하였다. 또한, 본 연구를 통하여 개발된 추정식을 이용하여 기존 손상선박의 처짐원인 분석, 거주구 탑재 및 진수 전후의 기관실 상갑판의 처짐거동 그리고 기존의 선각품질관리기준이 기관실 상갑판의 처짐에 미치는 영향을 살펴보았고, 마지막으로 건조예정에 있는 기관실의 처짐현상을 예측하여 보았다.

• 한국해양환경ㆍ에너지학회지
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• 제10권4호
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• pp.211-217
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• 2007

새로운 공격 무기들의 등장과 적과의 전투환경 변화로 현대의 함정설계에 있어 생존성의 향상은 가장 중요한 요소가 되었으며, 특히 적에게 쉽게 노출되는 수상함에 있어서는 생존성의 취약성에 대비한 감소대책이 보다 강조되고 있다. 생존성을 고려한 함정설계를 위하여 우선 적절한 공격 시나리오를 설정하고 이에 따라 폭발해석을 수행하여야 한다. 폭발은 함의 국부 손상 및 대변형 손상을 야기시키며 이 때 손상된 함정에 대한 적절한 생존성 평가가 중요하다. 본 연구에서는 구조-유체 연성기법 중 하나인 ALE기법을 적용하여 폭발해석을 수행하고 함정의 붕괴거동을 조사하였으며 이 손상된 함정에 대하여 정량적으로 생존시간을 계산할 수 있는 간략계산법을 제시하였다.

• 한국항해학회지
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• 제21권3호
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• pp.83-90
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• 1997

Damage stability is generally very important as a part of rescue technique of damaged ship and also in connection with the requirements of MARPOL73/78[2]. Damage stability calculation program has been developed and suggest, which can be used on an onboard computer for any operating drafts. The program is based on lost buoyancy method for calculation of final drafts, and also based on added mass method for calculation of residual righting arm. The numerical method suggested by Hamamoto-Kim[6] is adopted for calculation of intact righting arm(GZ). The model experiments on damage stability are also carried out in a small tank with tanker model 2.385 meters long. The experimental results are compared with the calculations by the suggested method.