• Journal of the Society of Naval Architects of Korea
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• v.29 no.2
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• pp.30-37
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• 1992

Since a ship is a complex steel construction which consists of sculptured surfaces and inner surface members, a high technique of information modeling is indispensable to describe the form of hull surface and steel structure members consistently. A model contains both topological and geometrical information of the structural members. Therefore, the hull form should be represented by the wireframe of surface model so that the accuracy in each design stage is satisfied. The structural members like plane surfaces, stiffeners and the relations between such members are to be described systematically in data base. A collection of the data stored in database is a model to be built. The model will be used not only to generate the drawings and documents for ship design and production but also to interconnect other systems such as compartmentation, outfitting, piping, etc. Computer graphics is adopted of the visualization of model.

• Bulletin of the Society of Naval Architects of Korea
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• v.30 no.4
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• pp.27-32
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• 1993

본 연구에서는 첫째로, 자체적으로 정립한 시스템 개발방법론인 객체지향 기술을 적용하여 선 체설계 전산시스템의 요구사양 및 기능분석을 수행하여, 유닛모델 개념(선체의 각 부분에서 보 여지는 특징적인 구조를 유닛으로 하고 선체구조정보를 설계변수화하여 파라메트릭 설계기법을 이용하여 모델링하는 방법임)의 초기 선체 모델링기법을 제시하고 이를 검증하므로써, 유조선 화물창부의 초기 모델링을 통한 구조설계 대안의 신속한 검토와 초기물량의 정확한 산출이 가 능하도록 하였다. 둘째로, 모델링 기술 분야에서는, 선박제품 모델링을 위한 기반 기술로써(여 기서, 제품모델링이란 최근 CAD/CAM 및 CIM 분야에서 거론되는 기술분야로서, 설계 및 생산의 대상이 되는 제품의 제반정보를 전산기 내에서 모델로써 표현하고자 하는 시도임) 선박 제품 모델의 표현방법론과 내부처리 기법을 정의하였고, 이 방법론에 다라 객체지향 구\ulcorner배치 프로 그램(OO_COMDEF)을 개발하여 본 연구에서 제시한 제품모델의 표현방법론을 검증하였다. 셋 째로 응용 프로그램 개발 분야에서는 선체 상세설계를 지원할 수 있는 시스템 설계를 수행하 였고, 이를 토대로 이중선체 유조선의 화물창부의 Hopper Tank부의 Stiffener 배치를 자동적으로 생성할 수 있는 시험용 프로그램을 개발하여 그 개념을 검증하였다.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.3
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• pp.1-11
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• 1994

The development of "Ship structural CAD system" has been performed in CSDP(Computerized Ship Design and Production) project to support ship structural design works. The procedures and contents of current design practice concerning the ship structural design were analyzed. To generate design information required at each design stage using the ship structural CAD system, the computerized model was created. To represent and implement the model information, a data structure which represents design concept as well as shape information was proposed using the concept of the product model. To embody the computerized model the object-oriented techniques were established to represent requirements of real world.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.4
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• pp.66-74
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• 1996

In this paper, a 3-dimensional ship structural model which includes the longitudinals and stiffeners is constructed. This model can be constructed from the well-defined data structure which represents the ship structural members and their relationship. So the object-oriented concept for the data structure is introduced. The structural analysis model is automatically generated by extracting the necessary information for structural analysis from the ship structural model : Users need to handle the ship structural model only when any design change occurs because the structural analysis model is automatically generated.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.12-20
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• 1991

The informations of ship structural design have been represented as the form various drawing plants, but to enhance the design productivity, it is necessary to utilize the advanced technologies such as CAD system and database management system. In this study, efforts are focused on the data modelling of those informations of midship configuration and attribute for the integration of ship structural design programs through database system. As actual example, midship configuration of bulk carrier was visualized by computer graphics. Relational data model is employed and topological informations is used for the best treatment of geometries representing structural arrangement. RDBMS 'ORACLE' was used for the implementation of the results.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.3
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• pp.90-99
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• 1993

As the finite element method has become a considerable and effective design tool in ship structural analysis, modeling of three dimensional finite element mesh is more necessary than before. However, the unique style and complexity of a ship usually make the modeling be hard and costly. Although most pre-processor of FEM software and geometric modeler provides modeling function, the capability is quite limited for complicated structure. In order to perform FEM modeling quickly, it is necessary to extract, rearrange, and formalize data from ship design database for partially automatic mesh generation. In this paper, the process of designing relational data tables from design data is shown as a part of analysis automation with the application of engineering database concept.

• Bulletin of the Society of Naval Architects of Korea
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• v.26 no.4
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• pp.57-66
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• 1989

In this paper, a theory for the static analysis of large plastic deformations of 3-dimensional frames, aiming at application to the collapse analysis of ship structures, is presented. In the frame analysis formulation, effects of shear deformations are included. A plastic hinge is inserted into the field of a beam end, and post. failure deformation of the plastic hinge is characterized by finite rotations and extensions. In order to model deep web frames of ship's structures into a framed structures, collapse of thin-walled plate girders is investigated. The proposed analysis method is applied to several ship structural models in the references.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.2
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• pp.44-55
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• 1996

Since the use of computer for the ship structural design around mid 1960``s, specially many researches on the midship section optimum design were carried out from 1980. For a rule-based optimum design case, there has been a problem of handling a discrete design variable such as plate thickness for a practical use. To deal with the discrete design variable problems and to develop an effective new method using artificial neural network for the ship structural design applications, Neuro-Optimizer combing Hopfield Neural Network and other Simulated Annealing is proposed as a new optimization method and then applied to the fundamental skeletal structures and Midship section of Tanker. From the numerical results, it is confirmed that Neuro-Optimizer could be used effectively as a new optimization method for the structural design.

• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.137-141
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• 2004

Ship structures are basically an assembly of plate elements and the load-carrying capacity or the ultimate strength is one of the most important criteria for safety assessment and economic design. Also, Structural elements making up ship plated structures do not work separately, resulting in high degree of redundancy and complexity, in contrast to those of steel framed structures. To enable the behavior of such structures to be analyzed, simplifications or idealizations must essentially be made considering the accuracy needed and the degree of complexity of the analysis to be used. On this study, to investigate effect of modeling range, the finite element method are used and their results are compared varying the analysis ranges. The model has been selected from bottom panels of large merchant ship structures. For FEA, three types of structural modeling are adopted in terms of the extent of the analysis. The purpose of the present study is to numerically calculate the characteristics of ultimate strength behavior according to the analysis ranges of stiffened panels subject to uniaxial compressive loads.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.2
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• pp.96-110
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• 1996

Aging ships can suffer structural damage due to corrosion, fatigue crack etc., and possibility of catastrophic failure of seriously damaged ships is very high. To reduce the risk of loss of ships due to hull collapse, it is essential to evaluate ultimate hull strength of aging ships taking into account various uncertainties associated with structural damages. In this paper, ultimate strength-based reliability analysis of ship structures considering wear of structural members due to corrosion is described. A corrosion rate estimate model for structural members is introduced. An ultimate limit state function of a ship hull is formulated taking into account corrosion effects. The model is applied to an existing oil tanker, and reliability index associated with hull collapse is calculated by using the second-order reliability method (SORM). Discussions on structure safety of corroded ships are made.