• International Journal of Naval Architecture and Ocean Engineering
• /
• v.11 no.1
• /
• pp.44-51
• /
• 2019

Designing sophisticate ship structures that satisfy several design criteria simultaneously with minimum weight and cost is an important engineering issue. For a ship structure composed of a shell and stiffeners, this issue is more serious because their mutual effect has to be addressed. In this study, a two-stage optimization method is proposed for the conceptual design of stiffeners in a ship's prow. In the first stage, a topology optimization method is used to determine a potential stiffener distribution based on the optimal results, whereupon stiffeners are constructed according to stiffener generative theory and the material distribution. In the second stage, size optimization is conducted to optimize the plate and stiffener sections simultaneously based on a parametric model. A final analysis model of the ship-prow structure is presented to assess the validity of this method. The analysis results show that the two-stage optimization method is effective for stiffener conceptual design, which provides a reference for designing actual stiffeners for ship hulls.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.3
• /
• pp.290-301
• /
• 2013

The docking analysis of a global ship structure is requested to evaluate its structural safety against the reaction forces at supports during docking works inside a dry dock. That problem becomes more important recently as the size of ships is getting larger and larger. The docking supports are appropriately arranged in a dock to avoid their excessive reaction forces which primarily cause the structural damages in docking a ship and, up to now, the structural safety has been assessed against the support arrangement by the finite element analysis (FEA) of a global ship structure. However, it is complicated to establish the finite element model of the ship in the current structural design environment of a shipyard and it takes over a month to finish the work. This paper investigates a simple and fast approach to carry out a ship docking analysis by a simplified grillage model and to assign the docking supports position on the model. The grillage analysis was considered from the motivation that only the reaction forces at supports are sufficient to assess their arrangement. Since the simplified grillage model of the ship cannot guarantee its accuracy quantitatively, modeling strategies are proposed to improve the accuracy. In this paper, comparisons between the proposed approach and three-dimensional FEA for typical types of ships show that the results from the present grillage model have reasonably good agreement with the FEA model. Finally, an integrated program developed for docking supports planning and its evaluation by the proposed approach is briefly described.

• Proceedings of KOSOMES biannual meeting
• /
• 2003.11a
• /
• pp.7-11
• /
• 2003

Ship is being operated under a highly dynamic environments and many factors are related with ship's collision and those factors are interacting. So, an analysis on the ship's collision causes is very important to prepare countermeasures which will ensure the safe navigation. And the analysis confirmed that ship's collision is occurred most frequently and the cause is closely related with human factor. The main purpose of this study is to build a model of human factors in ship's collision cause using SD(System Dynamics} approach and to measure a effect which is risk control countermeasures of ship's collision. To achieve this aim, the structure analysis on the causes of ship's collision using FSM are performed, and the structure was changed by quantitative, qualitative factors and their feedback loops in casual map. This model was performed over 20 years(1993-2012) in a standard simulation model and 8 policy simulation models.

• Journal of Navigation and Port Research
• /
• v.27 no.5
• /
• pp.493-498
• /
• 2003

Ship is being operated under a highly dynamic environments and many factors are related with ship's collision and those factors are interacting. So, An analysis on the ship's collision muses is very important to prepare countermeasures which will ensure the safe navigation. And the analysis confirmed that ship's collision is occurred most frequently and the muse is closely related with human factor. The main purpose of this study is to build a model of human factors in ship's collision muse using SD(System Dynamics} approach and to measure a effect which is risk control countermeasures of ship's collision. To achieve this aim, the structure analysis on the muses of ship's collision using FSM are performed, and the structure was changed by quantitative, qualitative factors and their feedback loops in casual map. This model was performed over 20 years(1993-2012) in a standard simulation model and 8 policy simulation models.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2003.10a
• /
• pp.348-356
• /
• 2003

Recently, the buckling is easy to happen a thin plate and High Tensile Steel is used at the steel structure and marine structure so that it is wide. Especially, the post-buckling is becoming important design criteria in the ship structure to use especially the High Tensile Steel. Consequently, it is important that we grasp the conduct post-buckling behaviour accurately at the stability of the ship structure or marine structure. In this study, examined closely about conduct and snap-through behaviour after initial buckling of thin plate structure which apply compressive load according to various kinds initial deflection shape under all edges simply supported condition that make by buckling formula in each payment in advance rule to place which is representative construction of hull. Analysis method is F.E.M in used ANSYS program and complicated nonlinear behaviour to analyze such as secondary buckling with snap-through behaviour. Nonlinear buckling control is applied between newton-raphson method and arc-length method in this study

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.11a
• /
• pp.655-660
• /
• 2000

Machines on board a ship are mounted on decks and transmit its structure-borne sound to the deck through resilient mounts. To predict the ship noise generated by the structure-borne sound of the machine, It is necessary to estimate the vibration level of the base structure. In this paper, a simple dynamic model is considered for vibration isolation systems consisting of a source, an isolator, and a base structure. The high frequency mobilities of the simple base structure are reviewed and wave effects in the mount are discussed in relation to isolation performance.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2002.11a
• /
• pp.101-105
• /
• 2002

FRP(Fiber glass reinforced plastics) is compound with materials, which are created to combine each other materials, of which nature of mechanical and chemical are different. Even though the weight and the thickness are identic, its physical figure of characteristic changes with consisting of lay-up and work situation. It is also a method of creating after manufacturing of mould. It has feature that manufacturing of FRP runs parallel design of material with design of structure simultaneously. The rule of FRP structure is distinguished from the length of a ship and it is hard to catch the feature of structure mechanics due to identical formula and figure used for it regardless of the shape of a ship or the speed. This studying, basing on a small FRP ship, will show te fundamental data needed to design of structure analysing the feature of intensity with direction, the method of Lay-up, and the characteristic of materials of FRP.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2002.10a
• /
• pp.245-250
• /
• 2002

This report describes the effects of following flaws due to ship's propeller on the fish farm structure when the ship's propeller is operated in full power. This study is applied an incompressible newtonian fluid theory, which is governed the Navier-Stokes equation. For the numerical solution, Neumann equation are applied as the boundary conditions. The result shows that the flow velocity near the fish farm is 1.0 m/sec. The actual measurement carries out by using propeller type velocimeter in order to measure the velocity of following flows and currents around the fish farm area. The result shows that the maximum velocity near the fish farm structure is 1.2 m/sec in depth of 1.5 m. This velocity is used for calculation of external force on the fish farm structure. The results of structural strength of the fish farm structures show that the actual maximum bending moment and bending stress are less than the damage strength of material. So the fish farm structure is not affected by the following flows and currents of ship's propeller.

• Journal of Advanced Navigation Technology
• /
• v.20 no.2
• /
• pp.116-126
• /
• 2016

In this study, has designed the ship application system for efficient data integration management of onboard ship and shore application/service utilizing data collected onboard ship, and has implemented the module. In order to supports onboard ship and shore service utilizing onboard ship collected data and provide a easy to access among individual devices, the ship application system applied the XML structure of ISO 16425 and the data sharing system model discussed in IALA, and the common module for system operation, a windows service for data collection/integral management, and web service module for management has been implemented.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.11a
• /
• pp.147-148
• /
• 2008