• 한국기계가공학회지
• /
• 제7권2호
• /
• pp.3-7
• /
• 2008

A polishing machine adopting a new unique structural mechanism has been developed, named as a swing-arm type polishing machine. The mechanism is such that the tool path tracks on a spherical surface, of which the diameter is adjusted by setting up the machine mechanism properly. It has a strong benefit especially for polishing axis-symmetric concave mirror surfaces. The swing-arm type polishing machine with 5-axes has been designed in order to polish a concave mirror surface lip to diameter of 2 meters. The drawings are made using 3D CAD and strain-stress analysis has been done by finite element method. AC servo-motor has been used to move the swing arm and a operating software has been developed using a LapVIEW tool. Result of the test run was satisfactory which convinces the usefulness of the swing-arm type polishing machine.

• 한국해양공학회지
• /
• 제34권3호
• /
• pp.217-226
• /
• 2020

An offshore plant is an offshore platform that can process oil and gas resources in rough seas with a poor working environment. Moreover, it is a complex structure with different types of offshore facilities and a large amount of outfitting that connects different offshore installations. In particular, an enormous amount of various piping materials is installed in a relatively narrow space, and thus, the difficulty of working is relatively high compared to working in ships or ground plants. Generally, when the 3D detailed design is completed, an offshore plant piping process is carried out at the shipyard with ISO 2D fabrication drawings and ISO 2D installation drawings. If a worker wants to understand the three-dimensional piping composition in the working area, he can only use three-dimensional viewers that provide limited functionality. As offshore plant construction progresses, correlating work with predecessors becomes more complicated and rework occurs because of frequent design changes. This viewer function makes it difficult to identify the 3D piping structure of the urgently needed part. This study deals with the process support method based on a system using a 3D simulator to improve the efficiency of the piping process. The 3D simulator is based on the Unity3D engine and can be simulated by considering the classification and priority of 3D models by the piping process in the system. Further, it makes it possible to visualize progress information of the process. In addition, the punch content can be displayed on the 3D model after the pipe inspection. Finally, in supporting the data in relation to the piping process, it is considered that 3D-simulator-supported piping installing could improve the work efficiency by more than 99% compared to the existing method.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2005년도 제24회 춘계학술대회논문집
• /
• pp.305-308
• /
• 2005

본 논문은 30ton급 액체로켓엔진 연소기의 연소시험 검증용 제작에 관한 것이다. 기본설계와 상세설계를 통해 도면을 작성하고, 이에 따라 제작하였다. 연소기는 크게 헤드부와 챔버부로 구성되며, 챔버는 KSR-III에 적용되었던 내열재 챔버와 재생 냉각 방식의 챔버를 제작하였다. 연소기 헤드는 저온 특성이 좋은 SUS316L 재료를 사용하였다. 내열재 챔버는 내부는 silica/phenolic 재료를 사용하였고, 외부케이스는 SUS316L을 적용하였고, 재생 냉각 챔버는 C18200과 SUS316L 재료를 사용하였다. 선반 가공, 일반 밀링 가공, MCT 가공등의 기계적 가공을 한 후 전해 연마를 통해 이물질을 제거 하였다. 분사기와 분사기 플레이트의 접합과 재생 냉각 챔버 등 일부 부품의 접합은 구조적인 특성으로 인해 브레이징 기법을 적용하였다.

• 한국BIM학회 논문집
• /
• 제8권2호
• /
• pp.41-50
• /
• 2018

The current study focused on the utilization of building information modeling (BIM) data in steel-frame structures, which help to reduce project durations because they employ prefabricated structural members that are assembled on-site. In addition, a business process model was proposed using BIM data collected during the preconstruction, structural steel fabrication, and on-site construction phases of an actual steel-frame project. The ultimate expectation is that BIM data support at each phase, as well as the increased understanding among project participants, will result in an increase in project management productivity. The results from the current study are summarized as follows: To implement a BIM capable of application to steel-frame projects and data utilization, existing theories were studied to develop the construction project steps, both generally into the preconstruction (A1), steel fabrication (A2), and on-site construction phases, (A3) and specifically into 19 BIM-applicable phases. Based on the derived BIM-applicable phases, the model elements of the BIM object were identified, and the shortcomings of existing steel-frame projects were ameliorated, resulting in an improved data flow model. Moreover, for the proposed BIM data flow to progress efficiently, the BIM specialist needs to be well-acquainted with the phase-specific three-dimensional (3D) model output, and the infrastructure to construct an error-free 3D model must be provided. Based on the actual construction example, the BIM data utilized steel-frame projects - via production reports, clash checks, two-dimensional (2D) drawings, four-dimensional (4D) simulations, and 3D scanning - to make cooperation and communication among participants easier.

• 한국건축시공학회지
• /
• 제8권1호
• /
• pp.83-90
• /
• 2008

The reinforcing steel process is composed of the development of placing drawing, cutting and bending, and the placement and fabrication of the reinforcement, and is participated in by reinforcement detailer, the fabricator and placer. Because the reinforcing steel process-from estimating and rebar detailing, to production, material tracking, billing, and general accounting-is conducted by many participant, reinforcement details based on building code and reinforcing bar detailing standards are essential. The process, however, holds some problems. Building code has been revised recently, and the utilization of placing drawings was proved to be low, and the reinforcement estimating in early stage of the process is below what is required for placement. Therefore, in this study, a survey was conducted to the reinforcement detailer, the fabricator and placer of domestic construction industry. According to the analysis of the survey, the reinforcement details on site was not standardized. The improvement in reinforcing steel detailing standards was sought by analyzing the results of the survey including reinforcement constructability.

• 대한조선학회논문집
• /
• 제56권1호
• /
• pp.66-74
• /
• 2019

In the field of shipbuilding design, the use of 3D CAD is becoming commonplace, and most of the large shipyards are conducting 3D design. However at the production site, workers are still working on 2D drawings rather than 3D models. This tendency is even worse in small-scale shipyards and block manufacturing shops. Particularly, in a manufacturing shop that is engaged in the outsourcing of blocks, it may not be possible to provide 3D model. However, the demand for 3D models in the production field is steadily increasing. Therefore, it would be helpful if 3D model could be generated from a 2D drawing. In this paper, we propose a method to extract template and unfolded surface shape information from shell template offset drawing using computer vision technology. Also a 3D surface model was reconstructed and visualized from the extracted information. The result of this study is thought to be helpful in the work environment where 3D model information can not be obtained.

• 한국산학기술학회논문지
• /
• 제21권2호
• /
• pp.58-65
• /
• 2020

3D CAD 시스템으로 설계된 해양플랜트 배관재 모델들은 2D 배관 제작도와 설치도의 형태로 생산 공정에 제공되고, 기본 엔지니어링 정보와 함께 통합 공정관리시스템에서 원자재의 구매, 조달, 제작, 설치 및 검사가 체계적으로 관리되어 진행된다. 기존의 통합 공정관리시스템은 자원의 흐름 및 진행 상황을 체계적으로 관리하여 공정 시수 절감에 많은 기여를 하고 있지만, 3D 설계 형상 모델 정보를 포함하고 있지 않기 때문에 배관 설치 작업 전에 복잡한 배관 구조를 파악하거나, 잦은 설계 변경으로 인해 연관된 도면을 찾을 때 상호간 신속한 정보 교류가 어려운 단점을 가지고 있었다. 이러한 문제점을 해결하기 위해 3D 모델을 기반으로 하는 해양플랜트 배관 공정 모니터링 시스템을 개발하였다. 본 시스템은 3D 모델 기반 배관 모니터링 시스템은 Visual Studio 2017 C#과 UNITY3D를 기반으로 배관 공정 작업 정보가 3D CAD 모델과 실시간 연동될 수 있도록 구성하였다. 그리고 블록, 크기, 재료에 따른 배관 설치 공정 진행 흐름 뿐만 아니라, 청소, 수압검사, 공압검사 등 기능 검사 항목별 진행 흐름을 3D 모델상에서 실시간으로 확인할 수 있도록 하였다. 작업자는 개발된 시스템을 통해 생산 현장에서 실시간으로 배관 공정 진행 흐름을 포함한 3D CAD 모델을 쉽게 파악함으로써 작업 효율성 향상에 많은 기여를 할 것으로 기대된다.

• 한국전산구조공학회논문집
• /
• 제29권1호
• /
• pp.77-83
• /
• 2016

선박 및 플랜트의 배관은 제작부터 설치까지 일련의 과정을 모두 현장에서 하는 것이 아닌, 외부의 공장 또는 숍으로부터 배관의 제일 작은 요소인 스풀 배관을 제작하고, 이를 작업현장 또는 현장 근처의 공장에서 모듈화 또는 가설치 작업 및 현장에서 직접 설치작업을 통해 제작이 된다. 이 과정에서 스풀은 3D CAD를 기반으로 하는 것이 아닌 2D 도면을 기반으로 하기 때문에, 작업공간을 고려하지 못할 수 있다. 이러한 이유로 실제 설치작업 시 작업공간의 방해로 인한 공기의 지연을 발생 시킬 수 있다. 본 논문은 이러한 스풀 배관의 설치 시 또는 운용 및 유지보수 시에 생길 수 있는 외부 구조물과의 스풀 위치에 관하여, 스풀 위치가 외부 구조물로부터 방해를 받지 않도록 하기 위한 방법으로 유전 알고리즘을 적용하여 스풀 위치를 결정하는 방법에 대해 제시하고자 한다.