• Computational Structural Engineering
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• v.22 no.4
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• pp.89-94
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• 2009

최근에 선박의 도킹해석은 3차원 전선 구조 해석을 통해 수행되어 왔으나 도킹해석 모델을 구성하는데 많은 시간과 노력이 필요하였다. 전선구조해석 모벨을 만들기 위해 필요한 선박구조 도면이 완성되기 전인 초기 설계단계에서 도킹시 반목배치를 조기에 확정하고, 구조 안정성을 확보하기 위한 노력이 요구되어 왔기 때문에 간이화된 도킹 해석 프로그램을 개발하게 되었다. 2차원 격자구조를 이용한 도킹해석기법을 통해 얻은 반목에서의 지지력이 3차원 전선해석모델을 사용하여 얻은 반목에서의 반력 결과와 비교해 타당한 결과를 보여 주고 있음을 확인하였다. 간이화된 도킹용 해석 프로그램을 개발하였으며, 다음과 같은 기능을 갖추어 사용자가 쉽게 격자 구조 모델을 생생하고 해석을 수행할 수 있도록 구성하였다. 향후 각 요소의 단면 특성치를 자동으로 산정하는 기능이 추가되어야 한다. 그리고 부유식 도크(Floating dock)에서의 도킹해석은 본 개발의 대상이 된 건식 도크(Dry dock)에서의 경우와 다른 고려사항이 추가되어야 하기 때문에 향후 추가적인 연구와 개발을 통해 새로운 기능으로 포함될 것이다.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.2
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• pp.90-95
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• 2017

In case of working for the construction of blocks of any ship in a floating dry dock, there may exist deflection in the pontoon deck of the floating dock due to the ballast loading and the self weight of the ship and the floating dock. This paper is on the development of the measuring system and the GUI program to show the real time variation of the deflections at even-spaced positions by several pressure gages and the calculated inclination of the floating dock. The measured and calculated data produced by this developed system could be used to prepare the protection plan on site like ballast adjustment to ensure the safety of working during the floating dock operation.

• Geotechnical Engineering
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• v.25 no.10
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• pp.35-45
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• 2009

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.399-404
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• 2015

The cost of fuel in ships has recently increased due to a rapid increase in international oil prices and international restrictions regarding the greenhouse effect generated from the burning of fuel. Therefore, different methods for changing the hull designs for improving energy efficiency, developing coating for reducing friction resistances, developing additives for improving engine thermal efficiency, and low-speed operation for reducing fuel consumption have been considered. The developments of high-speed, large-scale, and energy-saving vessels are deemed essential to adapt to the recent high oil price era. Therefore, it is important to analyze Precisely the qualitative and quantitative changes in the resistance value of the local areas of the hull surface. In this study, the engine performance before and after docking was analyzed to examine friction resistance caused by marine growth on the hull as a basic study for improving the energy efficiency. The result was then presented by comparing it with the previous data for 2.5 years between docks to investigate the performance of the main engine, the change in friction resistances and loads, the fuel consumption and ship speed.

• Economic and Environmental Geology
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• v.42 no.6
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• pp.549-559
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• 2009

The objectives of this study are to investigate the biomineralization of goethite and lepidocrocite formed on the twisted-stalk and the sheathed-filament structure that is suggest microbe origin, and heavy metal in the yellow Fe-hydroxide. On the ratio of Cl and the Cl/Br ratios that are a pollution and non-pollution of groundwaters, it is indicated that the groundwater in this areas were relatively contaminated by human activity. The composition of the yellow Fe-hydroxide consisted mainly of $Fe_2O_3$ and $SiO_2$. The content of $Fe_2O_3$ ranges from 58.57 wt.% to 75.7 3wt.%, and $SiO_2$ content ranges from 5.8 wt.% to 16.17 wt.%. Heavy metal elements such as Zn(max. 6,160 mg/kg), Pb(max. 377 mg/kg), U(max. 503 mg/kg), Cr(max. 203 mg/kg), Cu(max. 77 mg/kg), V(max. 162 mg/kg), Ni(max. 105 mg/kg) were observed to be rich in those yellow Fe-hydroxide. The lath and platy crystals and needle-shaped crystals were clearly observed on the twisted-stalks and sheathed-filaments structure. The goethite, gypsum, and lepidocrocite were identified in the yellow Fe-hydroxide by x-ray powder diffraction.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1267-1273
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• 2022

Although the Korea shipbuilding industry has recently been receiving most of the orders for ships in the world, production processes are being disrupted due to a shortage of manpower at the production site. This is because the workers quit the shipyard as both work and wages were reduced due to the long slump in the shipbuilding industry. The main reason for the increase in orders was the large-scale orders for Qatar LNG carriers, and the situation in which the technical specifications required for ships are becoming more complex is also working to an advantage. Because the contract delivery time is of utmost importance for ships, the dock launch plan is the most important management item among the shipyard's major processes. The structure to be built in the dock may be a hull that has left the design work or a finished vessel, and in some cases, it is often at the level of some blocks of the hull. When launching, the hull is affected by the hogging or sagging moment due to the fluid force, and securing the safety of the structural strength of the block connection is of utmost importance. In a normal process, the connecting member launches after welding has been completed, but in actual shipbuilders, quick decision-making is needed on the conditions for securing structural safety to comply with the docking schedule. In this study, a detailed analysis method and applicability using a bending stress evaluation method and finite element analysis modelling were analyzed to rationally judge the above-mentioned problems from an engineering point of view. The main contents mentioned in the thesis can be used as good examples when conducting similar structural strength evaluations in the future.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.276-278
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• 2004

조선업계에서 선체 건조 시 정도관리는 부재가 공, 조립, P/E 및 도크 작업에 이르는 일련의 흐름을 원활하게 하는 핵심기술이다. 조립과정에서 누적되는 여러 가지 변형 오차를 교정하기 위한 작업들로 인해 생산성이 저하되고 있다. (중략)

• Proceedings of the Korean Magnestics Society Conference
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• 1992.10a
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• pp.58-59
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• 1992

• Journal of the Society of Naval Architects of Korea
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• v.36 no.1
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• pp.53-60
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• 1999

Prior to sea trials, dock trials are usually carried out in order to check the main propulsion system and auxiliaries. At that time the motion of a ship is limited by mooring ropes. In Hyundai Heavy Industries, a simple equation is used to obtain propeller thrust which is used as an input data of mooring analysis. Recently the ship size and the engine power become larger. Therefore a careful analysis of the mooring condition is necessary in order to avoid possible accidents. In this study propeller thrust at deck trials is reviewed and examined through a series of model tests.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.509-519
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• 2015

Mooring stability of floating dock for construction of Ichthys CPF (central processing facilities), an ultra large offshore structure, was studied. Normal and typhoon conditions were considered for mooring analysis. There have been changes in construction stages of the CPF as project progresses. These changes were reflected on the mooring stability analysis for both conditions. In order to secure the mooring stability of the floating dock for Ichthys CPF under typhoon, maximum loads of mooring chains and maximum offset of the floating dock with Ichthys CPF were examined. Also the shapes of the catenary mooring were investigated to check interferences among mooring chains. As it was confirmed that the mooring loads were within SWL (safe working load) of mooring chains and underwater sinkers, the mooring stability of the floating dock for construction of Ichthys CPF was secured. By achieving security of mooring stability of the floating dock, it is assured that Ichthys project is on its way to success.