• Title/Summary/Keyword: Elastica Theory

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Buckling Loads and Post-Buckling Behavior of Clamped-Free Columns with Constant Volume (일정체적 고정-자유 기둥의 좌굴하중 및 후좌굴 거동)

  • 이병구;오상진;모정만;진태기
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.3-10
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    • 1996
  • Numerical methods are developed for solving the buckling loads and the elastica of clamped- free columns of circular cross-section with constant volume. The column model is based rut the Timoshenko beam theory. The Runge-Kutta and Regula-Falsi methods, respectively, are used to solve the governing differential equations and to compute the eigenvalues. Extensive numerical results, including buckling loads, elastica of buckled shapes and effects of shear de-formation, are presented in non-dimensional form for elastic columns whose radius of circular cross-section varies both linearly and parabolically with column length.

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Geometrical Non-linear Analyses of Tapered Cantilever Column Subjected to Sub-tangential Follower Force (경사 종동력을 받는 변단면 기하 비선형 캔틸레버 기둥의 수치해석)

  • Lee, Byoung-Koo;Oh, Sang-Jin;Lee, Tae-Eun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.1
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    • pp.29-38
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    • 2013
  • This paper deals with geometrical non-linear analyses of the tapered cantilever column subjected to the sub-tangential follower force at the free end. Cross-sections of the column whose flexural rigidities are functionally varied with the axial coordinate. The differential equations governing the elastica of such column are derived on the basis of the large deformation theory. These differential equations have three unknown parameters of the vertical and horizontal deflections and rotation at the free end. These differential equations are numerically solved by the iteration technique for obtaining three unknowns and elastica of the deformed column. For validating theories developed herein, laboratory scaled experiments are conducted.

Gemetrical Non-Linear Behavior of Simply Supported Tapered Beams (단순지지 변단면 보의 기하학적 비선형 거동)

  • 이병구
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.41 no.1
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    • pp.106-114
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    • 1999
  • This paper explores the geometrical non-linear behavior of the simply supported tapered beams subject to the trapezoidal distributed load and end moments. In order to apply the Bernoulli -Euler beam theory to this tapered beam, the bending moment equation on any point of the elastical is obtained by the redistribution of trapezoidal distributed load. On the basis of the bending moment equation and the BErnoulli-Euler beam theory, the differential equations governging the elastical of such beams are derived and solved numerically by using the Runge-Jutta method and the trial and error method. The three kinds of tapered beams (i.e. width, depth and square tapers) are analyzed in this study. The numerical results of non-linear behavior obtained in this study from the simply supported tapered beams are appeared to be quite well according to the results from the reference . As the numerical results, the elastica, the stress resultants and the load-displacement curves are given in the figures.

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Non-Linear Behavior of Tapered Simple Beam with a Floating Concentrated Load (변화위치 집중하중을 받는 변단면 단순보의 비선형 거동)

  • 이병구
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.42 no.2
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    • pp.108-114
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    • 2000
  • This paper explores the non-linear behavior of tapered beam subjected to a floating concentration load. For applying the Bernoulli-Euler beam theory to this beam, the bending moment at any point of elastical is obtained from the final equilibrium stage. By using the bending moment equation and the Bernoulli-Euler beam theory, the differential equations governing the elastica of simple beam are derived , and solved numberically . Three kinds of tapered beam types are considered . The numerical results of the non-linear behavior obtained in this study are agreed quite well to the results obtained from the laboratory-scale experiments.

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The Simulation and Experiment of Flexible Media with High Exit Velocity (고속의 출구속도를 가지는 유연매체의 거동해석 및 실험)

  • Hong, Sung-Kwon;Jee, Jung-Geun;Jang, Yong-Hoon;Park, No-Cheol;Park, Young-Pil
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.380-383
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    • 2006
  • The media transport system is used in a printer, a ATM(Automated Tellor Machine), and so on. The media transport system has many problems through miniaturization and rapid transportation of these machines. In the paper feeding mechanism, it is important to feed the sheet without jamming under any conditions. To avoid sheet jamming, first we need to predict the behavior of the sheet exactly. In this paper, the analysis of media behavior is based on J. Stolte's studies. In all of OA machines, a flexible beam or plate is pushed from the channel. The motion may be constrained by guides. This leads to a transient and geometrically nonlinear problem. The behavior of paper is simulated by dynamic elastica theory. The shape of guide is represented by parametric cubic curve. But J. Stolte's studies did not considered contact condition between sheet and guide. So Klarbring's Model. will be applied. And the analysis of flexible media has to include aerodynamic effect for more exact behavior analysis, because the flexible media can be deformed drastically by a little force. Therefore aerodynamic force must be applied to the governing equation. Lastly, the simulation of this model is performed, and the experiment is performed for verification of this model. The experimental results of low exit velocity are consistent with the simulation results, however experimental results of high exit velocity do not agree well with analytical results. The reason is that there may be other effects like nip Phenomena

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Geometrical Non-linear Analyses of Tapered Variable-Arc-Length Beam subjected to Combined Load (조합하중을 받는 변단면 변화곡선 보의 기하 비선형 수치해석)

  • Lee, Byoung-Koo;Oh, Sang-Jin;Lee, Tae-Eun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.2
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    • pp.129-138
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    • 2012
  • This paper deals with geometrical non-linear analyses of the tapered variable-arc-length beam, subjected to the combined load with an end moment and a point load. The beam is supported by a hinged end and a frictionless sliding support so that the axial length of the deformed beam can be increased by its load. Cross sections of the beam whose flexural rigidities are functionally varied with the axial coordinate. The simultaneous differential equations governing the elastica of such beam are derived on the basis of the Bernoulli-Euler beam theory. These differential equations are numerically solved by the iteration technique for obtaining the elastica of the deformed beam. For validating theories developed herein, laboratory scaled experiments are conducted.

Non-Linear Behavior of Shear Deformable Simple Beam with a Concentrated Load (전단변형을 고려한 집중하중을 받는 단순보의 비선형 거동)

  • 이병구;이태은;안대순;김권식
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.04a
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    • pp.53-60
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    • 2003
  • This paper explores the governing differential equations for the non-linear behavior of shear deformable simple beam with a concentrated load. In order to apply the Bernoulli-Euler beam theory to simple beam, the bending moment equation on any point of the elastica is obtained by concentrated load. The Runge-Kutta and Regula-Felsi methods, respectively, are used to integrate the governing differential equations and to compute the beam's rotation at the left end of the beams. The characteristic values of deflection curves for various load parameters are calculated and discussed

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Buckling oad and Post-buckling Behavior of Tapered Column with Constant Volume and Both Clamped Ends (일정체적 양단고정 변단면 기둥의 좌굴하중 및 후좌굴 거동)

  • 이병구
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.41 no.5
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    • pp.112-122
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    • 1999
  • 이 논문은 일정체적을 갖는 양단고정 변단면 기둥의 좌굴하중 및 후좌굴 거동에 관한 연구이다. 기둥의 변단면으로는 직선형, 포물선형, 정현의 선형을 갖는세 가지 변단면을 채택하였다. Bernoulli-Euler 보 이론을 이용하여 압축하중이 작용하여 좌굴된 기둥이 정확탄성곡선을 지배하는 미분방정식을 유도하였다. 유도된 미분방정식을 Runge-Kutta 법과 REgula-Falsi법을 이용하여 수치해석하였다. 수치해석의 결과로 좌굴하중, 좌굴기둥의 평형경로 및 정확탄성곡선을 산출하였다. 또한 좌굴하중-단면비 곡선으로부터 최강기둥의 좌굴하중과 단면비를 산출하였다.

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Large deflections of variable-arc-length beams under uniform self weight: Analytical and experimental

  • Pulngern, Tawich;Halling, Marvin W.;Chucheepsakul, Somchai
    • Structural Engineering and Mechanics
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    • v.19 no.4
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    • pp.413-423
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    • 2005
  • This paper presents the solution of large static deflection due to uniformly distributed self weight and the critical or maximum applied uniform loading that a simply supported beam with variable-arc-length can resist. Two analytical approaches are presented and validated experimentally. The first approach is a finite-element discretization of the span length based on the variational formulation, which gives the solution of large static sag deflections for the stable equilibrium case. The second approach is the shooting method based on an elastica theory formulation. This method gives the results of the stable and unstable equilibrium configurations, and the critical uniform loading. Experimental studies were conducted to complement the analytical results for the stable equilibrium case. The measured large static configurations are found to be in good agreement with the two analytical approaches, and the critical uniform self weight obtained experimentally also shows good correlation with the shooting method.

Geometrical Nonlinear Analyses of Post-buckled Columns with Variable Cross-section (후좌굴 변단면 기둥의 기하 비선형 해석)

  • Lee, Byoung Koo;Kim, Suk Ki;Lee, Tae Eun;Kim, Gwon Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1A
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    • pp.53-60
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    • 2009
  • This paper deals with the geometrical nonlinear analyses of post-buckled columns with variable cross-section. The objective columns having variable cross-section of the width, depth and square tapers are supported by both hinged ends. By using the Bernoulli-Euler beam theory, differential equations governing the elastica of post-buckled column and their boundary conditions are derived. The solution methods of these differential equations which have two unknown parameters are developed. As the numerical results, equilibrium paths, elasticas and stress resultants of the post-buckled columns are presented. Laboratory scaled experiments were conducted for validating the theories developed in this study.