• 제목/요약/키워드: Top-down design

검색결과 238건 처리시간 0.036초

상하향식 설계법을 이용한 자동차 배기시스템의 설계 (Design of Automobile Exhaust System using a Top-Down Approach Design Methodology)

  • 고병갑;박경진
    • 한국자동차공학회논문집
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    • 제5권6호
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    • pp.13-27
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    • 1997
  • In the modern design technology, a component should be designed to fit into the overall system performance. A design methodology is developed to expedite the mechan- ical design of complex mechanical systems, The relation between the system design and component design is defined by a top-down approach and the results from the system design are utilized in the component design process. As a design example, an automobile exhaust system is selected for the system design and a bellows is chosen for a component design. Design methodology based on the top-down approach consists of five steps; (1) Analysis of service load, (2) Development of a lumped parameter, (3) Completion of the system design, (4) Selection of the component topology, (5) Completion of the component design, A method using a equivalent matrix is developed in order to determine unknown external forces in linear structural analyses. The bellows is also analyzed by the finite element method using a conical frustum shell element. Various experiments are performed to verify the developed theories. The top-down desi- gn approach is demonstrated by a design case using structural and shape optimization technology. Since the method is relatively simple and easy compared to other methods, it can be applied to the general design where system and component designs are involves simultaneously.

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기계 제품의 개념 설계를 위한 하향 설계 지원 CAD시스템의 개발 (Framework of a CAD System to Support Design Process Modeling of Mechanical Products)

  • 홍진웅;이건우
    • 한국CDE학회논문집
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    • 제5권4호
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    • pp.359-372
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    • 2000
  • Current CAD systems are good enough to be used as a tool to manipulate three-dimensional shapes. This is a very important capability to be owned by a design tool because a major portion of designers'activities is spent on the shape manipulation in the design detailing process. However, the whole design process involves a lot more than the, shape manipulation. Currently, these remaining tasks, mostly logical reasoning process for the function realization together with structure decomposition in the top-down manner, are processed in the designer's brain. To support the top-down functional design process of a mechanical product, a system integrating the functional, structural and geometrical aspects of a product design in a unified environment is presented. Using this system, a designer can perform function decomposition, structure decomposition, and geometry detailing, and function verification activities in parallel and the whole design process it modeled resultantly. Once the whole design process is modeled, any redesign task can be automatically performed with the verification of the desired functions.

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건축 구조체를 이용한 개량 역타공법 적용시 흙막이 벽체의 거동 연구 (A Study on the Behavior of the Retaining Walls with the Improved Top-Down Support System using the Building Structure)

  • 천병식;노배영;도종남;유우현
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.1666-1672
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    • 2008
  • In this study, it collected and analyzed a construction case of the improved top-down support system application field on a case by case retaining wall method. The behavior of horizontal displacement was analyzed according to retaining wall type after reviewing a design stage and estimated horizontal displacement under the construction. The study results showed that it is judged stable until excavation termination irrelevant to a retaining wall method at the improved top-down support system application. It is judged that the settlement of behind ground can minimize because the retaining wall head displacement also behave stably. It was compared the predicted horizontal displacement in design and the measured horizontal displacement acquired through a measurement by using Elasto-Plastic analysis program. The comparison results showed that a similar horizontal displacement was predicted within stability standard irrelevant to a retaining wall method. So, it is decided that the advanced prediction is reasonable by Elasto-Plastic analysis in design applied the improved top-down support system. In the case of the ground anchor method application under a same condition, it is decided that a horizontal displacement will more increase than the improved top-down support system is applied. If a section condition is same, it was decided that to apply top-down support system is more stable than that.

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Top-Down 공법이 적용된 흙막이벽의 역해석을 이용한 거동분석 (The Behavior of Earth Retaining Walls Applied to Top-Down Construction Method Using Back Analysis)

  • 홍원표;강철중;윤중만
    • 지질공학
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    • 제22권1호
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    • pp.39-48
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    • 2012
  • 본 연구에서는 흙막이벽 설계시 널리 사용되고 있는 SUNEX 프로그램을 이용하여 Top-Down 공법이 적용된 지중연속벽, 주열식 흙막이벽(CIP벽, SCW벽)의 변형거동을 분석하였다. 해석프로그램에 Rankine의 토압(1857), Terzaghi and Peck의 토압(1967), Tschebotarioff의 토압(1973), 홍원표 윤중만의 토압(1995a)을 적용하여 흙막이벽의 수평변위를 예측하였다. 프로그램 해석결과, 흙막이벽의 수평변위량은 토압의 종류에 따라 큰 차이를 나타내고 있다. 홍원표 윤중만의 토압(1995a)을 적용하여 얻은 흙막이벽의 예측수평변위량이 실측수평변위량과 가장 유사하게 나타났다. 따라서 프로그램 해석시 홍원표 윤중만의 경험토압(1995a)을 적용하면, Top-Down 공법이 적용된 흙막이벽의 변형거동을 비교적 정확히 예측할 수 있다.

제품정보관리 시스템 개발을 위한 기능 분석에 관한 연구 (A Study on the Functional Requirement Analysis for the Development of PDM System)

  • 한관희;박찬우
    • 한국CDE학회논문집
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    • 제7권1호
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    • pp.42-56
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    • 2002
  • Presented in this study is a top-down functional requirement analysis procedure and the desired functionalities for PDM system development, and the benefits of top-down approach over a conventional bottom-up approach is also shown. For the purpose of top-down requirement analysis for PDM system, this study proposes 4P modeling view. 4P modeling view is defined as a modeling perspective for classifying functional requirements and integrating product-related information objects that must be man-aged within PDM systems. Based on 4P modeling templates, benchmarking analysis of commercially major PDM products is conducted and as a result of this analysis, this study suggests desired functionalities for PDM system.

하향식 설계방식을 지원하는 새로운 개념의 CAD 시스템 (CAD System of New Concept to Support Top-Down Approach in Design)

  • 김성환;이건우
    • 대한기계학회논문집
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    • 제19권7호
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    • pp.1604-1618
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    • 1995
  • In the process of mechanical assembly design, assembly modeling systems have been used mainly for the design verification before manufacturing by enabling to check the interference and/ or the dynamic and kinematic performance. However, the conventional assembly modeling systems have a shortcoming that they can not be used in the initial design stage but can be used only after the design is fully completed. In other words conventional assembly modeling systems provide bottom-up modeling which means that the detailed modeling of components must precede the definition of relationships between them. To resolve this problem, an assembly modeling system is proposed to provide a top-down modeling environment in which components and assembly can be modeled simultaneously. To this end, an assembly data structure suitable for top-down assembly modeling has been established. Feature positioning Module(FPM) using geometric constraints has been also developed. The Sekective Solving Method proposed for FPM is based on the priority between the constraint equations and enables the designer's intent expressed by geometric constraints to be maintained throughout the whole modeling process. Finally, the feature based modeling technique using two-level features has been developed. Two-level features include an abstract model and a detailed model in a merged form in non-manifold data frame.

Top-Down 방식의 주거개념 크루즈선 설계 (A Cruise Ship Design with Residence Concept through Top-Down Sequential Procedure)

  • 이한석;변량선;조성철;김동준;현범수;최경식
    • 한국항해항만학회지
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    • 제28권10호
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    • pp.843-850
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    • 2004
  • 본 연구에서는 지역적 문화적으로 특색을 달리하는 크루즈 모델 개발의 한 방안으로서 미래지향적 주거개념의 크루즈선 설계모델을 제시하였다. 크루즈선 설계를 위해서는 조선공학, 건축디자인, 경영경제학 등의 복합지식이 요청되고 있다. 본 연구에서는 선박의 하부구조 결정을 통해 초기 선형을 도출한 후 기본설계에 들어가는 기존의 조선설계 방법과는 반대로 상부구조의 건축디자인 작업이 먼저 착수되는 Top-Down 방식의 접근방법을 채택하였다.

Top-Down 공사용 선기초기둥의 특성 (Specificity of Prefounded Column for Top-Down Construction)

  • 강승룡;임홍철;김승원;박대영;김동건;송지윤;정미라
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2008년도 추계 학술논문 발표대회
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    • pp.135-139
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    • 2008
  • For deep basement construction of buildings downtown, the usage of Top-Down Method is increasing as much as ever from strong demand. One of the essential elements for the construction by Top Down Method is the pre-founded columns, which are installed in the ground and on which a building is installed. The fact that the pre-founded columns are placed in the ground makes them susceptible to its plumbness; this aspect distinguishes pre-founded columns from general columns. However, there are no criteria for erection tolerance. Therefore, field-measured-data concerning out-of-plumb of pre-founded columns in the construction field should be accumulated and investigated so that criteria and specifications for the erection tolerance of pre-founded columns may be established through the understanding of its aspects. In this paper, we investigate out-of-plumb of pre-founded columns for the construction case and analyze its aspects, and propose considerations for design and construction phase.

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