• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2009년 추계학술대회논문집
• /
• pp.71-76
• /
• 2009

The research to predict the resistance performance of the ship using the CFD analysis is increasing. For the CFD numerical analysis the computational mesh, which is proper to computational model, has to be made before the analysis is begun. In the parametric study, even though the deformation of each case is not very sharp, the whole computational mesh should be regenerated according to the conventional way. Hence, lots of effort is needed to repeated mesh generation work. To solve these problems, the automatic mesh generation method using the macro function of commercial CAD program and mesh generation program is introduced in this study. First, in the CAD program, by using the macro function and putting the deformation rate of bow and stern in lengthwise, the repeated modeling work is performed automatically. Next, the generated geometries are read by the mesh generation program and the proper mesh for the geometry is created automatically also using the macro function. The hybrid mesh which has unstructured grid near the bow and stern and structured grid in the remaining part of domain is used. The verification of the developed method is done by applying the method to predict the resistance performance of the podded propulsion cruise ship of the Daewoo Shipbuilding & Marine Engineering (DSME) in the cases of different length of bow and stern and pod set in different position. The author believes that the introduced method can help to make the database to optimize the resistance performance of the ship in various cases can be constructed without difficulty.

• 한국추진공학회지
• /
• 제3권1호
• /
• pp.55-64
• /
• 1999

대형 조선소에서는 선박에 사용하고 있는 수많은 부재들은 고가이고, 고급기술을 필요로 하는 WORK-STAT10N급에서 구동되는 선박전용프로그램 등에 의하여 부재생성 및 네스팅을 하고 있다. 그러나 중소형 조선소의 경제적, 기술적인 사정으로 고가의 장비와 고급인력의 확보가 어려운 실정이다. 따라서 본 연구에서는 널리 보급되어 있는 PC에서 사용 가능한 파라메트릭 매크로에 의한 부재생성과 부재의 네스팅 프로그램을 개발하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.552-552
• /
• 2000

In recent years, a number of successful nesting approaches have been developed by using the various heuristic algorithms, and due to their application potential several commercial CAD/CAM packages include a nesting module for solving the layout problem. Since a large portion of the complexity of the part nesting problem results from the overlapping computation, the geometric representation is one of the most important factors to reduce the complexity of the problem. The proposed part representation method can easily handle parts and raw materials with widely varying geometrical shape by using the redesigning modules. This considerably reduces the amount of processed data and consequently the run time of the computer. The aim of this research is to develop parametric macro for two-dimensional cutting stock on the Auto-CAD system. Therefore, this research can be called "pre-nesting"

• 한국해양공학회지
• /
• 제13권2호통권32호
• /
• pp.176-185
• /
• 1999

Currently, large size shipyards have performed the generating of piece and the nesting using shipbuilding-oriented CAD program, which requires high skilled operator and costs a lot. So, medium and small size shipyards have pursued other way to obtain the generating and the nesting due to an economic and a technical problems. Therefore, this research is to develop a program for the generating of pieces with parametric macro method and a STRIP program for the nesting of pieces by PC.

• 한국정밀공학회지
• /
• 제18권5호
• /
• pp.23-28
• /
• 2001

• 한국해양공학회지
• /
• 제33권3호
• /
• pp.205-213
• /
• 2019

Recently, because of the global recession of the offshore plant industry and low-cost orders, there has been increasing interest in strengthening the competitiveness of domestic companies for the design and production technologies of offshore plants. However, in the offshore plant design field, the Plant Design Management System (PDMS), which is a 3D CAD program for plant layout developed by AVEVA Marine, is already commonly used as offshore plant design software and widely used in large domestic shipyards and cooperative design companies. Under this background, we have been thinking about ways to design better with the existing software. In this study, we developed a parametric design program to maximize the efficiency and reduce the working time for offshore plant electrical outfit production design based on the Programmable Macro Language (PML) of PDMS. We also examined its performance. By applying the developed program to the offshore plant module selected as an application example, it was confirmed that a 50% improvement in the work efficiency of cable tray design could be obtained compared with the existing method, with work efficiency improvements of 80% or more in other field design work.

• 한국CDE학회논문집
• /
• 제9권3호
• /
• pp.226-237
• /
• 2004

If the topology changes in the re-generation step of the history-based and feature-based CAD systems, it is difficult to identify an entity in the old model and find the same entity in the new model. This problem is known as 'persistent naming problem'. To exchange parametric CAD models, the persistent naming problem and the naming mapping problem must be solved among different CAD system, which use different naming scheme. For CAD model exchange the persistent naming has its own characteristics compare to that for CAD system development. This paper analyses previous researches and proposes a solution to the persistent naming problem for CAD model exchanges and to the naming mapping problem among different naming schemes.

• 한국산학기술학회논문지
• /
• 제20권2호
• /
• pp.632-637
• /
• 2019

해양 플랜트 전장생산설계의 케이블 트레이 설계는 구조 부재 및 각종 의장 장비들과 간섭없이 케이블이 설치될 수 있도록 3D 모델링하여 원활하게 최적 배치하는 작업으로, 대부분 PDMS(Plant design management system)를 이용하여 수행되고 있다. PDMS는 해양 플랜트 생산설계 전용 3D CAD 시스템으로 국내 조선소와 관련 설계협력업체에서 널리 사용되고 있다. 본 연구에서는 PDMS 기반 해양 플랜트 케이블 트레이 설계 지원 PML(Programmable macro language)을 개발하여, 기존 방법 대비 업무 효율성을 검토하였다. 개발된 케이블 트레이 설계 PML은 전장 템프릿 라이브러리를 이용하여 완전히 파라메트릭 설계가 가능하도록 함으로써 설계 변경으로 인한 빈번한 수정 작업에 신속히 대응할 있도록 하였고, 축적된 설계 경험를 반영하여 반복되는 작업 피로를 최소화할 수 있도록 하였다. 그리고 개발된 시스템을 해양 플랜트 구조 모듈에 적용하여 기존 방법 대비 약 50% 이상의 작업 효율성 향상이 예상됨을 확인하였다.

• 소성∙가공
• /
• 제12권4호
• /
• pp.314-319
• /
• 2003

In the micro hole punching, the size and shape of burr and burnish zone are very important factors to evaluate quality of micro holes which depend on punch-die clearance, strain rate, workpiece material and etc. To get micro holes with small burr and wide burnish zone for industrial demands, not only the parametric study but also a study on fracture behavior in shear band are necessary. In this study, 100 $\mu$m, 25 $\mu$m micro holes in diameter were fabricated on brass (Cu63/Zn37) and SUS 316 foils as aspect ratio 1:1, and the characteristics of micro holes was investigated comparing with those of macro holes over several mm by scanning electron microscopic views and section views. Like macro hole, micro hole is also composed of 4 portions, rollover. burnish zone, fracture zone and burr, and it shows similar fracture behavior in shear band. But by high strain rate (10$^2$∼10$^3$s$^{-1}$ ) condition unlike that of macro hole fabrication and by the increment of relative grain size in the direction of the workpiece thickness, fracture zone is not observed.

• Structural Engineering and Mechanics
• /
• 제36권3호
• /
• pp.247-278
• /
• 2010

The study of the seismic vulnerability of masonry buildings requires structural properties of walls such as stiffness, ultimate load capacity, etc. In this article, a method is suggested for modeling the masonry walls under in-plane loading. At the outset, a set of analytical equations was established for determining the elastic properties of an equivalent homogeneous material of masonry. The results for homogenized unreinforced brick walls through detailed modeling were compared in different manners such as solid and perforated walls, in-plane and out-of-plane loading, etc, and it was found that this method provides suitable accuracy in estimation of the wall linear properties. Furthermore, comparison of the results of proposed modeling with experimental out coming indicated that this model considers the non linear properties of the wall such as failure pattern, performance curve and ultimate strength, and would be appropriate to establish a parametric study on those prone factors. The proposed model is complicated; therefore, efforts need to be made in order to overcome the convergency problems which will be included in this study. The nonlinear model is basically semi-macro but through a series of actions, it can be simplified to a macro model.