• Title/Summary/Keyword: preliminary design procedure

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The Optimum Design of a Spatial 3-DOF Manipulator Using Axiomatic Design (공리적 설계를 이용한 공간형 3자유도 기구의 최적설계)

  • Han Seog Young;Yi Byung-Ju;Kim Seon Jung;Kim Jong O;Chung Goo Bong
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.6
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    • pp.52-60
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    • 2005
  • Ultra-precision positioning systems basically require high natural frequency and sufficient workspace. To cope with this requirement, flexure hinge mechanisms have been developed. However, previous designs are difficult to satisfy the functional requirements of the system due to difficulty in modeling and optimization process applying fur the independent axiomatic design. Therefore, this paper suggests a new design and design procedure based on semi-coupled, axiomatic design. A spatial 3-DOF parallel type micro mechanism is chosen aa an exemplary device. Based on preliminary kinematic analysis and dynamic modeling of the system, an optimum design is conducted. To check the effectiveness of the optimal parameters obtained by theoretical approach, simulation has been performed by FEM.

Structural Design on Joint Component of Composite Wing of WIG Craft

  • Lee, Younggyu;Park, Hyunbum
    • International Journal of Aerospace System Engineering
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    • v.8 no.2
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    • pp.1-3
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    • 2021
  • This study proposed a specific preliminary structural design procedure of the main wing for a small scale WIG vehicle to meet the target weight of the system requirement. The high stiffness and strength Carbon-Epoxy material was used for lightness, and the foam sandwich type structure at the upper skin and the spar webs was adopted for improvement of structural stability. After structural design, wing joint part was designed. Through investigation on structural design result, design modification was performed. After design modification, even thought the designed wing weight was a little bit heavier than the target wing weight, the structural safety and stability of the final design feature was confirmed.

Rotor design functional standard of Synchronous Reluctance Motor according to torque/volume using FEM & SUMT (유한요소법과 SUMT를 이용한 동기형 릴럭턴스 전동기의 토크와 부피에 따른 회전자 설계의 함수화)

  • Lee, Rae-Hwa;Lee, Jung-Ho
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.11
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    • pp.577-581
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    • 2006
  • This paper deals with an automatic rotor design functional standard computation based on torque/volume for a synchronous reluctance motor(SynRM). The focus of this paper is the design relative to the torque/volume on the basis of each rated watt according to the rotor diameters of a SynRM. The coupled finite elements analysis (FEA) & sequential unconstrained minimization technique (SUMT) have been used to evaluate design solutions. The proposed procedure allows to define the rotor geometric design function according to the rotor diameter and rated watt starting from an existing motor or a preliminary design.

Explicit expressions for inelastic design quantities in composite frames considering effects of nearby columns and floors

  • Ramnavas, M.P.;Patel, K.A.;Chaudhary, Sandeep;Nagpal, A.K.
    • Structural Engineering and Mechanics
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    • v.64 no.4
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    • pp.437-447
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    • 2017
  • Explicit expressions for rapid prediction of inelastic design quantities (considering cracking of concrete) from corresponding elastic quantities, are presented for multi-storey composite frames (with steel columns and steel-concrete composite beams) subjected to service load. These expressions have been developed from weights and biases of the trained neural networks considering concrete stress, relative stiffness of beams and columns including effects of cracking in the floors below and above. Large amount of data sets required for training of neural networks have been generated using an analytical-numerical procedure developed by the authors. The neural networks have been developed for moments and deflections, for first floor, intermediate floors (second floor to ante-penultimate floor), penultimate floor and topmost floor. In the case of moments, expressions have been proposed for exterior end of exterior beam, interior end of exterior beam and both interior ends of interior beams, for each type of floor with a total of twelve expressions. Similarly, in the case of deflections, expressions have been proposed for exterior beam and interior beam of each type of floor with a total of eight expressions. The proposed expressions have been verified by comparison of the results with those obtained from the analytical-numerical procedure. This methodology helps to obtain the inelastic design quantities from the elastic quantities with simple calculations and thus would be very useful in preliminary design.

An application of a Knowledge-Based System for Structural Planning (구조계획에서의 지식기반시스템 도입연구)

  • 김상철;김홍국;이병해
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1994.10a
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    • pp.137-144
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    • 1994
  • This study describes an application of a knowledge-based system for a part of the development of an integrated structural design system. In preliminary structural design procedure, most structural design operation are performed by structural engineer's manual method. These lack of systematic operation hampers the effective system integration. By introducing expert system to the structural planning stage, structural engineer can automate structural Planning process of an integrated structural design system for complex design. Engineering data management is receiving increasing attention due to complexity of information necessary for performing structural engineering operations. So, in this paper, we describe a methodology for automating conceptual structural design and developing a knowledge-based system integrated with database. At the end, we use an implemented example to support our methodology.

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Optimization of Steel Box Girder Highway Bridges Using Discrete Variables (이산형변수를 고려한 강박스거더교의 단면최적화)

  • 김상효;이상호;이민구
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.04a
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    • pp.195-202
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    • 1995
  • In this study, the optimization program is developed to provide preliminary designs of steel-box girder bridges with minimum cost. The advantages of steel-box girder deck, when comparing with other girder types, are higher torsional rigidity and better resistance against corrosion. To achieve more rational design, systematic design procedure is required, by which the design constraints on steel-box girder are satisfied and the design variables with minimum cost are obtained. In the Proposed optmum design Process, the design variables are forced to be selected from the available discrete value set. The efficiency of the developed program has been verified by companing with previous designed sections and the resulting optimum cost with discrete variables has been compared with those of continuous variables.

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A Development of Simplified Method for the Detention Pond Design with Runoff Reduction (유출저감용 저류지 설계를 위한 간이기법 개발)

  • Lee, Jae-Joon;Kwak, Chang-Jae;Kim, Ho-Nyun;Lee, Sang-Won
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.632-635
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    • 2007
  • Detention pond has an important role in peak flow reduction to mitigate flood damage. Design of detention pond is accomplished through the preliminary stage, planning stage, and design stage in general. New development projects produce increased peak flow and flow amounts. In this case it is necessary to design the detention pond easily and simply. The simple procedure of detention pond design is proposed in this study. The relevant variables are peak flow ratio ($\alpha$) for the before and after development, and storage ratio which is ratio of storage volume to flow amounts. Simplified method for the detention pond design with runoff reduction is easily used for practical purposes.

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Optimum Design Criteria for Maximum Torque Density and Minimum Torque Ripple of Flux Switching Motor using Response Surface Methodology

  • Lee, Jung-Ho;Lee, Tae-Hoon
    • Journal of Magnetics
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    • v.15 no.2
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    • pp.74-77
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    • 2010
  • This paper deals with optimum design criteria for maximum torque density & minimum torque ripple of a Flux Switching Motor (FSM) using response surface methodology (RSM) & finite element method (FEM). The focus of this paper is to find a design solution through the comparison of torque density and torque ripple which vary with rotor shape. And then, a central composite design (CCD) mixed resolution was introduced and analysis of variance (ANOVA) was conducted to determine the significance of the fitted regression model. The proposed procedure allows one to define the rotor dimensions, starting from an existing motor or a preliminary design.

Rotor design functional standard of Synchronous Reluctance Motor according to torque/volume using FEM & SUMT (유한요소법과 SUMT를 이용한 동기형 릴럭턴스 전동기의 단위부피당 토크에 따른 회전자 설계기준의 함수화)

  • Lee, Rae-Hwa;Lee, Jung-Ho
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.709-710
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    • 2006
  • This paper deals with an automatic rotor design functional standard computation based on torque/volume for a synchronous reluctance motor (SynRM). The focus of this paper is the design relative to the torque/volume on the basis of each rated watt according to the rotor diameters of a SynRM. The coupled finite elements analysis (FEA) & sequential unconstrained minimization technique (SUMT) have been used to evaluate design solutions. The proposed procedure allows to define the rotor geometric design function according to the rotor diameter and rated watt starting from an existing motor or a preliminary design.

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Optimum Design Criteria based on Capacity of Synchronous Reluctance Motor Using a Coupled FEM & SUMT (유한요소법을 이용한 동기형 릴럭턴스 전동기의 용량에 따른 회전자 구조설계와 SUMT를 이용한 최적설계)

  • Kwon, Sun-Bum;Kim, Gi-Bok;Lee, Jung-Ho
    • Proceedings of the KIEE Conference
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    • 2004.10a
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    • pp.126-128
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    • 2004
  • This paper deals with an automatic optimum design based on capacity for a synchronous reluctance motor (SynRM). The focus of this paper is the design relative to the output power on the basis of rotor shape of a SynRM in each capacity. And optimization algorithm is used by means of sequential unconstrained minimization technique(SUMT). The coupled Finite Elements Analysis (FEA) & Preisach model have been used to evaluate nonlinear solutions. The proposed procedure allows to define the rotor geometric dimensions according to capacity starting from an existing motor or a preliminary design.

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