• 대한조선학회논문집
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• 제55권5호
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• pp.379-384
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• 2018

This study showed the development process of structural design method of BHB(Blast Hardened Bulkhead) which are applicable in preliminary design stage. In the previous 1st report, the simplified structural scantling equations of BHB were formulated theoretically using the modified plastic hinge method supplemented by considering the membrane effects due to large plastic deformation. And the scantling methodology of plate thickness and section area of stiffeners of the curtain plate type BHB was dealt with. In the present 2nd report, derivation process of the correction factors which can adjust the developed scantling equations considering the uncertainties contained in the design parameters was introduced. Considering the actual BHB structures of 3 warship, the correction factors for the developed scantling equations for curtain plate type BHB were derived. Finally the applicability, validity of them and the strategy of future improvement were considered.

• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.32-42
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• 2007

Container vessels are required to have a large KMT to load many containers which requires a wide transom stern form. The wide transom stern generates large stern waves particularly at the scantling draft. This means that reducing the stern wave leads to resistance reduction. Numerical analyses and Model tests for duck-tail of the stern part have been performed to reduce the resistance of the container vessel having the wide transom on the scantling draft and optimize the form of duck-tail with the change of the design parameter i.e. length and edge height. The optimized duck-tail increases the speed by 0.8 % at scantling draft.

• Journal of Advanced Research in Ocean Engineering
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• 제4권1호
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• pp.7-15
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• 2018

The submarine is an underwater weapon system which covertly attacks the enemy. Pressure hull of a submarine is a main system which has to have a capacity which can improve the survivability (e.g., protection of crews) from the high pressure and air pollution by a leakage of water, a fire caused by outside shock, explosion, and/or operational errors. In addition, pressure hull should keep the functional performance under the harsh environment. In this study, optimal design of submarine pressure hull is dealt with 7 case studies done by analytic method and then each result's adequacy is verified by numerical method such as Finite Element Analysis (FEA). For the structural analysis by FEM, material non-linearity and geometric non-linearity are considered. After FEA, the results by analytic method and numerical method are compared. Weight optimized pressure hull initial scantling methods are suggested such as a ratio with shell thickness, flange width, web height and/or relations with radius, yield strength and design pressure (DP). The suggested initial scantling formulae can reduce the pressure hull weight from 6% and 19%.

• 대한조선학회논문집
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• 제30권2호
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• pp.155-160
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• 1993

본 논문은 선박 기관실의 특설늑골에 대한 치수결정 방법으로써 하나의 접근방법을 서술하였다. 특설늑골의 치수결정 인자는 실적선의 데이터를 중심으로 조사 연구되었으며, 그 구성인자로는 주로 갑판간 거리, 주기 및 프로펠러 기진 주파수, 만재흘수선, 특설늑골 배치간격, 갑판수 그리고 주기마력 등이다. 이러한 주요인자를 기초로 정하중 및 동하중이 고려된 특설 늑골 치수를 결정할 수 있는 설계식을 유도하였다. 본 논문은 기관실구조의 특설늑골의 치수를 검토할 수 있는 한 방법으로써 설계단계에서 정하중 및 동하중을 고려한 합리적인 설계가 될 수 있을 것으로 판단된다.

• 한국해양공학회지
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• 제34권4호
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• pp.263-271
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• 2020

In this study, we performed a three-dimensional (3D) topology optimization of a fixed offshore structure to enhance its structural stiffness. The proposed topology optimization is based on the solid isotropic material with penalization (SIMP) method, where a volume constraint is applied to utilize an equivalent amount of material as that used for the rule-based scantling design. To investigate the effects of the main legs of the fixed offshore structure on its structural stiffness, the leg region is selectively considered in the design domain of the topology optimization problem. The obtained optimal designs and the rule-based scantling design of the structure are manufactured by 3D metal printing technology to experimentally validate the topology optimization. The behaviors under compressive loading of the obtained optimal designs are compared with those of the rule-based scantling design using a universal testing machine (UTM). Based on the structural experiments, we concluded that by employing the topology optimization method, the structural stiffness of the structure was enhanced compared to that of the rule-based scantling design for an equal amount of the fabrication material. Furthermore, by effectively combining the topology optimization and rule-based scantling methods, we succeeded in enhancing the structural stiffness and improving the breaking load of the fixed offshore structure.

• 대한조선학회논문집
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• 제43권1호
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• pp.75-86
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• 2006

The scantling and structural design work is done during the initial stage in yacht design. This paper studies a procedure of the structural design for yacht with an illustrative design. Scantling of structural members and loads are defined based on the rules suggested by ISO(International Standard Organization) and ABS(American Bureau of Shipping). Also, FEA(Finite Element Analysis) model is presented for a practical guide for structural analysis. An equivalent structural element is used to simplify the composite material for the analysis.

• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.99-106
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• 2007

The IACS Common Structural Rules are to be applied for double hull tanker of more than 150m length with contracted after 1 April 2006. The objectives of the rules are to make more robust, safer ship and to ensure transparency of the technical background. In compliance of CSR, we had carried out prescriptive rules scantling determination and 3-D hold FE analysis of AFRAMAX TANKER. Prescriptive rules scantling determines the minimum required scantling, hull-girder longitudinal bending and shear strength, hull girder ultimate strength, local strength of plate and stiffener, strength of primary supporting member and fatigue assessment of the longitudinal stiffener end connections to the transverse bulkhead. 3-D hold FE analysis assesses the structural adequacy of the vessel's primary hull structure and major supporting members using yielding and buckling failure modes. So we could verify the strength assessment of AFRAMAX TANKER applied CSR.

• 대한조선학회논문집
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• 제30권2호
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• pp.30-36
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• 1993

본 논문에서는 설계 경험이 적은 설계자가 효율적으로 선급규정을 이용하여 선체설계를 할 수 있도록, 범용 전문가시스템 쉘(Shell)인 NEXPERT를 이용하여, 선체 구조설계를 지원할 수 있는 전문가 시스템을 개발하였다. 먼저, 기존의 Rule Scantling프로그램으로 부터 지식을 추출하고, 이를 바탕으로 객체지향개념에 의해 지식의 그룹핑과 계층화를 시도하였다. 또한, NEXPERT가 갖고 있는 외부 프로그램과의 접속기능(Callable Interface)을 이용하여 각종 설계에 필요한 프로그램과 실적선 데이타베이스를 접속하였다. 특히, Motif를 이용한 그래픽 사용자 인터페이스(Graphical User Interface : GUI)를 도입하였고, 설계자가 결과에 대해 검토를 할 수 있도록 Knowledge tracing 기능을 부여함으로써, 사용자 지향의 구조부재 치수 결정 지원 전문가 시스템을 개발하였다.

• 수산해양기술연구
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• 제51권1호
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• pp.9-15
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• 2015

A Korean-designed cruiser class sailing yacht, based on the form of traditional yachts, has been developed. In this paper, structural design procedures for the yacht are studied. The scantling of structural members and loads is carried out based on the guidelines suggested by Australian Standard 4132-1993, the American Bureau of Shipping (ABS) and the International Organization for Standardization (ISO). Patran/Nastran finite element analysis is performed on models of the trial sailing boat, and from these results, the structural strength of the ship's hull is verified.

• 대한조선학회논문집
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• 제42권6호
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• pp.644-653
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• 2005

In general the loads due to ocean wave are considered as main design parameters governing the global structural safety of VLFS (Very Large Floating Structure). In order to predict design wave loads accurately, hydro-elastic analysis must be conducted considering the initial global flexural rigidity of VLFS. However, in order to determine the structural scantling of major members (deck, bottom, side panels and longitudinal / transverse BHD etc.), static load and design wave loads must be given as explicit form generally. Therefore in order to determine a proper structural arrangement and scantlings of VLFS at initial design stage, both calculations of structural scantling and hydro-elastic analysis for wave conditions must be conducted iteratively and the convergence of their results must be checked. On this paper, based on the case design of a 500×300 m size's floating marina resort, the details of structural design technique using hydro-elastic analysis are explained and discussed. At first, the environmental conditions and the system requirements of the design of marina resort are described. The scantling formulas for the major members of pontoon type VLFS are proposed from the local and global design points of view. Considering the design wave loads as well as static design loads, the structural safety is checked iteratively.