• 대한조선학회 특별논문집
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• 대한조선학회 2015년도 특별논문집
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• pp.34-40
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• 2015

The design, procurement and fabrication of FPSO project ordered by Inpex Browse, Ltd. have been currently carried out by DSME(Daewoo Shipbuilding Marine and Engineering Co.). The unit will be installed and operated in the Ichthys field offshore of North-Western Australia and there are the particular design requirements to do with performance on the environment loads corresponding to max. 10,000 years return period wave. Also, the operational life of FPSO has to be over 40 years. With this background, this paper introduces the structural design procedure of crane pedestal foundation operated in north-western Australia offshore. The design of crane pedestal foundation structure is basically based on international design code (i.e. API Spec. 2C), Classification society's rule and project specifications. The design load cases are mainly divided into the crane normal operating conditions and crane stowed conditions according to environment conditions of the offshore with 1-year, 5-year, 10-year, 200-year and 10,000-year return period wave. This design experience for crane pedestal foundation operated in north-western Australia offshore will be useful to do engineering of other offshore crane structures.

• 대한조선학회논문집
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• 제45권1호
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• pp.87-92
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• 2008

In the load-carrying fillet weldments, which are common in ship structures, fatigue cracks can occur at the weld root, in addition to the weld toe. In particular, fatigue cracks originating from the weld root are difficult to detect and cause a significant reduction in the fatigue strength of a weldment. Therefore, it is important to note the fatigue failure mode of load-carrying fillet weldment. In this study, a series of fatigue test was carried out for the fatigue strength evaluation of longi-web connections that are typical kinds of the load-carrying fillet weldment.

• International Journal of CAD/CAM
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• 제6권1호
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• pp.3-8
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• 2006

The application of three-dimensional (3-D) CAD has been popularized for design and production and digital manufacturing has been spreading in many industrial fields. By simulation of the production process using 3-D digital models, which are the core of CIM (Computer Integrated Manufacturing) system, the efficiency and safety of production are improved at each stage of work, and optimization of manufacturing can be achieved. This paper firstly describes the concept of "simulation based production" in shipbuilding and also digital manufacturing; the 3-D CAD system is indispensable for effective simulation because ship structure is three dimensionally complex. By simulation, "computer optimized manufacturing" can be possible. The most effective fields of simulation in shipbuilding are in jobs where many parties have to cooperate, while existing two-dimensional drawings are hardly observed the whole structures due to interference between structures or equipment of complex shape. In this paper some examples of the successful application in IHIMU (IHI Marine United Inc.) are shown: assembly of a pipe unit, erection of a complex hull block, carriage of equipment, installation of a propeller, and access in an engine room.

• 대한조선학회논문집
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• 제45권1호
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• pp.81-86
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• 2008

Recently, a mesh-size insensitive structural stress definition that provides a stress state at weld toe with relatively larger mesh size compared to conventional approaches has been proposed. The structural stress definition is based on the elementary structural mechanics theory and provides an effective measure of a stress state in front of weld toe. In this study, as an experimental validation of structural stress method in obtaining the fatigue strength of weldments, a series of fatigue test has carried out for longi-web connections, which are representative of ship-like structures. Based on the result from this study, it is expected to develop a more precise fatigue strength evaluation technique and to reduce time and cost associated with the fatigue design of ship and offshore structures.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.76-83
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• 2005

Membrane type LNG Carriers are characterized by their special structures such as trunk deck above upper deck. It is necessary to introduce an appropriate structure arrangement taking into account transition of the trunk deck to the upper deck or deckhouse in fore and aft parts. The transition area at aft part -from trunk deck to the deckhouse - is to be specially considered because of high longitudinal stresses applied at the area. This study has been carried out to tackle the transitional structure problem in design stage This paper deals with not only mesh size of FE models for scantling evaluation and fatigue assessment but also technical issues regarding fatigue assessment.

• Journal of Advanced Marine Engineering and Technology
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• 제37권6호
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• pp.589-595
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• 2013

본 논문은 플라즈마 절단 면 특성이 I Groove 서브머지드 아크 용접 용락 현상에 미치는 영향과 용락 현상을 감소시키는 방법에 대하여 연구하였다. 조선해양 구조물의 주판은 대부분 후판으로 설계되고 깊은 용입을 얻기 위하여 고 전류를 사용하게 된다. 용접부의 절단 품질에 따라서 서브머지드 아크용접 진행 시 용락 현상이 자주 발생되고 이는 용접부의 품질 저하와 수정 작업을 유발시킨다. 본 연구의 플라즈마 절단 실험에서 나타난 특성으로 I형상 그루브 직각 절단 시 상,하면에 플라즈마 열원에 의한 녹음 현상과 함께 하면 한 방향에 약 2~4도 정도의 각 변형 베벨이 형성됨을 확인하였다. 이는 맞대기 이음에서 용락 현상의 주된 원인이며 모재 절단 시 상면 방향에 I 그루브 형상에 가깝도록 한 방향 기준으로 V형상 그루브 4도 베벨을 시공하여 서브머지드 아크 용접을 실시한 결과 용락 현상을 현저히 저감시키는 결과를 얻을 수 있었다.

• 대한지리학회지
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• 제39권1호
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• pp.116-131
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• 2004

본 연구의 목적은 조선산업 하청구조의 공간 특성을 고찰하는 것이다. 오늘날 기업은 다른 기업과 연관된 생산시스템을 통하여 기업의 목표를 달성해 나간다. 복잡하고 거대한 플랜트를 건조하는 조선산업의 하청구조는 모기업과의 거래관계를 규정하는 공간적 요인에 따라 상이한 특성을 보이고 있다. 우선 모기업의 생산공정에 직접 참여하는 사내하청기업이나 사외지역의 협동화단지업체들은 분사화된 특성을 보이면서 밀접하게 연결되어 있다. 그리고 기계산업으로 특화되어 있는 창원이나 전통적으로 조선기자재산업이 발달한 부산지역 업체들은 전문화의 정도가 상대적으로 높아 하청관계가 비교적 강하게 연결되어 있다. 이에 비해 비국지적으로 분포하거나 표준화된 제품을 공급하는 하청기업들은 대부분 연결도가 낮게 나타난다. 조선산업의 성숙한 발전을 위해서는 모기업 주변의 사내ㆍ외지역에 집적하는 조선전문 하청기업들과의 집중적 협력과 함께 기술적으로 특화된 원거리 업체들과의 선택적 거래관계를 강화해야 할 것이다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.707-717
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• 2021

To the date, shipbuilding companies have applied shop primer coating which protects the steel surface from global oxidization in environment. Proper shop primer requires either anti-corrosion ability during construction or anti-porosity ability during welding, and those properties contradict to each other. This report tried to derive an optimizing parameter on these conflicting properties to select a proper shop primer. First, sufficient amounts of the natural salt spray tests were carried out to achieve a series of data for the anti-corrosion ability. Second, lots of T-joint fillet welding test were performed to evaluate the trapped porosity formed in the weld pool. According to the experimental data, we could achieve either the rust-formation rate or the porosity-formation rate, then, each rate was generalized as formulae. Then, we tried to combine these conflicting properties to decide an optimum shop primer.

• 한국해양공학회지
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• 제22권2호
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• pp.20-27
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• 2008

A moon-pool is a vertical well in a floating barge, drilling ship, or offshore support vessel. In this study, numerical simulation of two-dimensional moon-pool flaw coupled with a ship's motion in waves is carried out using a particle method, the so-called MPS method. The particle method, which is recognized as one of the gridless methods, was developed to investigate nonlinear free-surface motions interacting with structures. The method is more feasible and effective than convectional grid methods in order to solve a flaw field with complicated boundary shapes.

• 대한조선학회논문집
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• 제45권4호
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• pp.426-431
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• 2008

The high-strength low-alloy(HSLA) steels have low carbon contents($0.05{\sim}0.25%$ C) in order to produce adequate formability and weldability, and they have manganese contents up to 1.7%. Small quantities of silicon, chromium, nickel, copper, aluminum, molybdenum are used in various combinations. The results contained in this paper can provide the valuable information on the development of $-40^{\circ}C$ low temperature HSLA. Furthermore, the present experimental data will provide important database for casting steel materials of the offshore structure.