• Title/Summary/Keyword: Structural Constraint

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A Study on the Evaluation of Dynamic Characteristics of the Optmized Shells (최적화된 쉘의 동특성 분석 및 평가에 대한 연구)

  • Lee Sang-Jin;Kim Ha-Ryong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.341-346
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    • 2006
  • This paper provides the resuIts on the evaluation of dynamic characteristics of the optimized shells. Five fundamental technologies such as computer-aided geometric design, automatic mesh generation, shell finite element, design sensitivity analysis and shell optimization process, are used for shell optimization maximizing the fundamental natural frequency. A dome shell is adopted for the shell shape optimization and the dynamic characteristic of the optimized shell such as the variation of natural frequencies is then investigated. From the investigation, more constraint functions related to shell natural frequencies is necessarily required to effectively control dynamic characteristics of the optimized shells.

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Buckling Loads and Post-Buckling Behavior of Linear Tapered Columns (선형 변단면 기둥의 좌굴하중 및 후좌굴 거동)

  • Lee Tae-Eun;Ahn Dae-Soon;Lee Seung-Woo;Park Kwang-Kyou
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.689-696
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    • 2006
  • This paper deals with the geometrical non-linear analyses of the buckled columns. Differential equations governing elasticas of the buckled columns are derived, in which both effects of taper type and shear deformation are included. Three kinds of taper types such as breadth, depth and square tapers are considered. Differential equations are solved numerically to obtain the elasticas and buckling loads of such columns. End constraint of both clamped ends and both hinged ends are considered. The effects of shear deformation on the elastica of the buckled column and buckling load of column are investigated extensively. Experimental studies are presented that complement theoretical results of non-linear responses of the elasticas.

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Design of a Small Form Factor Swing Arm type Actuator using Design of Experiments (실험계획법을 이용한 초소형 스윙암 액추에이터의 설계)

  • Park Chul;Yoo Jeong-Hoon;Park No-Ceol
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.813-819
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    • 2006
  • The state of the art for the design of swing ann actuators for optical disc drives is to obtain the high efficient dynamic characteristics, especially for the small size for the mobile information devices, It is affected by the need of consumers who wants the portable digital storage devices maintaining highly functional and removable characteristics of the optical disk drive (ODD). As a necessary consequence, the need of the small form factor (SFF) storage device has been considered as an important part in the information storage technology. In this paper. we suggest a new conceptual miniaturized swing arm type actuator that has high efficient dynamic characteristics as well as satisfies the sensitivity and the heat emission requirements for the SFF-ODD. It also uses a tracking electromagnetic (EM) circuit for a focusing motion. Due to the size constraint, the thermal problem of optical head arises; therefore, we design an efficiently heat emitted structure for the actuator.

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Applications of MLS(Moving Least Sqrare)-based Finite Elements for Mechanics Problems Involving Interfaces and Discontinuities (경계 및 불연속의 해결을 위한 이동최소제곱 기반 유한요소의 적용)

  • Lim Jae-Hyuk;Im Se-Young;Cho Young-Sam
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.567-574
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    • 2006
  • We present applications of MLS-based finite elements, which enable us to easily treat highly complex nonmatching finite element meshes and discontinuities. The shape functions of MLS-based finite element can be easily generated with the aid of Moving Least Square approximation on the parental domain. The major advantage includes that the position of element nodes as well as the number of the element nodes can be conveniently adjusted according to the nature of the problems under consideration, so that finite-element mesh is straightforwardly adapted to evolving discontinuities and. interfaces. Furthermore, we show that the present MLS-based finite elements are efficiently applied for elastic-plastic deformations, wherein the implicit constraint of incompressibility should be properly handled.

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Robust Optimization Design of Overhead Crane with Constraint Using the Characteristic Functions

  • Hong, Do-Kwan;Choi, Seok-Chang;Ahn, Chan-Woo
    • International Journal of Precision Engineering and Manufacturing
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    • v.7 no.2
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    • pp.12-17
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    • 2006
  • This study uses a characteristic function to explain correlations between the objective function and design variables. For the use, structural analysis and buckling analysis are carried out. the dimensional change of an original overhead crane is made based on the table of orthogonal array. For two functions or more, the effectiveness of design change can be evaluated in accordance with change in design parameters. Also, the overhead crane's weight is reduced by up to 10.55 percent while its structural stability maintained.

Analytical Method for Constrained Mechanical and Structural Systems

  • Eun, Hee-Chang;Park, Sang-Yeol;Lee, Eun-Taik;Chung, Heon-Soo
    • Journal of Mechanical Science and Technology
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    • v.18 no.10
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    • pp.1691-1699
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    • 2004
  • The objective of this study is to present an accurate and simple method to describe the motion of constrained mechanical or structural systems. The proposed method is an elimination method to require less effort in computing Moore-Penrose inverse matrix than the generalized inverse method provided by Udwadia and Kalaba. Considering that the results by numerical integration of the derived second-order differential equation to describe constrained motion veer away the constrained trajectories, this study presents a numerical integration scheme to obtain more accurate results. Applications of holonomically or nonholonomically constrained systems illustrate the validity and effectiveness of the proposed method.

Optimum Design of the Spatial Structures using the TABU Algorithm (TABU 알고리즘을 이용한 대공간 구조물의 최적설계)

  • Cho, Yong-Won;Lee, Sang-Ju;Han, Sang-Eul
    • Proceeding of KASS Symposium
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    • 2005.05a
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    • pp.246-253
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    • 2005
  • The design of structural engineering optimization is to minimize the cost. This problem has many objective functions formulating section and shape as a function of the included discrete variables. simulated annealing, genetic algerian and TABU algorithm are searching methods for optimum values. The object of this reserch is comparing the result of TABU algorithm, and verifying the efficiency of TABU algorithm in structural optimization design field. For the purpose, this study used a solid truss of 25 elements having 10 nodes, and size optimization for each constraint and load condition of Geodesic one, and shape optimization of Cable Dome for verifying spatial structures by the application of TABU algorithm

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A Novel Image Completion Algorithm Based on Planar Features

  • Xiao, Mang;Liu, Yunxiang;Xie, Li;Chen, Qiaochuan;Li, Guangyao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.8
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    • pp.3842-3855
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    • 2018
  • A novel image completion method is proposed that uses the advantage of planar structural information to fill corrupted portions of an image. First, in estimating parameters of the projection plane, the image is divided into several planes, and their planar structural information is analyzed. Second, in calculating the a priori probability of patch and patch offset regularity, this information is converted into a constraint condition to guide the process of filling the hole. Experimental results show that the proposed algorithm is fast and effective, and ensures the structure continuity of the damaged region and smoothness of the texture.

Automatic Design of Steel Frame Using Nonlinear Analysis (비선형 해석을 이용한 강뼈대구조물의 자동화설계)

  • 김창성;마상수;김승억
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.287-294
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    • 2002
  • An automatic design method of steel frames using nonlinear analysis is developed. The geometric nonlinearity is considered by the use of stability functions. A direct search method is used as an automatic design technique. The unit value of each member is evaluated by using LRFD Interaction equation. The member with the largest unit value Is replaced one by one with an adjacent larger member selected in the database. The weight of the steel frame is taken as an objective function. Load-carrying capacities, deflections, interstory drifts, and ductility requirement are used as constraint functions. Case study of a three-dimensional two story frame are presented.

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Free Vibrations of Double Hinged Curved Beams with Clothoid Transition Segment (Clothoid 완화곡선을 갖는 양단회전 곡선보의 자유진동)

  • 이병구;진태기;최규문;김선기
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.04a
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    • pp.391-397
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    • 2001
  • This paper explores the free vibrations of double hinged curved beams with transition segment. In this study, the clothoid curve is chosen as the transition segment of beams. The differential equations governing free vibration of such beams are derived in which the effects of rotatory inertia and shear deformation are included. The Runge-Kutta method and Determinant Search method are used to perform the integration of differential equations and to compute natural frequencies, respectively. In numerical examples, the double hinged end constraint is considered. The lowest four natural frequencies are presented as functions of three non-dimensional system parameters: the slenderness ratio, shear parameter and stiffness parameter.

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