• 제목/요약/키워드: elastica

검색결과 55건 처리시간 0.029초

A NEW APPROACH ON THE CURVATURE DEPENDENT ENERGY FOR ELASTIC CURVES IN A LIE GROUP

  • Korpinar, Talat;Demirkol, Ridvan Cem
    • 호남수학학술지
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    • 제39권4호
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    • pp.637-647
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    • 2017
  • Elastica is known as classical curve that is a solution of variational problem, which minimize a thin inextensible wire's bending energy. Studies on elastica has been conducted in Euclidean space firstly, then it has been extended to Riemannian manifold by giving different characterizations. In this paper, we focus on energy of the elastic curve in a Lie group. We attepmt to compute its energy by using geometric description of the curvature and the torsion of the trajectory of the elastic curve of the trajectory of the moving particle in the Lie group. Finally, we also investigate the relation between energy of the elastic curve and energy of the same curve in Frenet vector fields in the Lie group.

Exact solutions of variable-arc-length elasticas under moment gradient

  • Chucheepsakul, Somchai;Thepphitak, Geeraphong;Wang, Chien Ming
    • Structural Engineering and Mechanics
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    • 제5권5호
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    • pp.529-539
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    • 1997
  • This paper deals with the bending problem of a variable-are-length elastica under moment gradient. The variable are-length arises from the fact that one end of the elastica is hinged while the other end portion is allowed to slide on a frictionless support that is fixed at a given horizontal distance from the hinged end. Based on the elastica theory, exact closed-form solution in the form of elliptic integrals are derived. The bending results show that there exists a maximum or a critical moment for given moment gradient parameters; whereby if the applied moment is less than this critical value, two equilibrium configurations are possible. One of them is stable while the other is unstable because a small disturbance will lead to beam motion.

일정체적 캔틸레버 기둥의 좌굴하중 및 후좌굴 거동 (Buckling Loads and Post-Buckling Behavio of Cantilever Column with Constant Volume)

  • 이승우;이태은;김권식;이병구
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2006년도 정기 학술대회 논문집
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    • pp.935-940
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    • 2006
  • Numerical methods are developed for solving the elastica and buckling load of cantilever column with constant volume, subjected to a compressive end load. The linear, parabolic and sinusoidal tapers with the regular polygon cross-sections are considered, whose material volume and span length are always held constant. The differential equations governing the elastica of buckled column are derived. The Runge-Kutta method is used to integrate the differential equations, and the Regula-Falsi method is used to determine the horizontal deflection at free end and the buckling load, respectively. The numerical methods developed herein for computing the elastica and the buckling loads of the columns are found to be efficient and reliable.

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Dynamic Elastica 이론을 통한 유연매체의 거동해석 및 실험 (The Simulation and Experiment of Flexible Media using Dynamic Elastics)

  • 홍성권;지중근;장용훈;박노철;박영필
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.569-572
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    • 2005
  • In many machines handling lightweight and flexible media, such as automated teller machines(ATM) and printers etc., the media must transit an open space. 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. The nonlinear theory of the dynamic elastica has often been used to a nonlinear dynamic deflection model. In this paper, the governing equation is derived and simulated by the finite difference method. The analysis has to include aerodynamic effect for more exact behavior analysis. For verification of the numerical simulation, the experiments were performed using high-speed camera and feeding mechanism. The experimental results show good agreement with the numerical simulations.

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Dynamic Elastica에 의한 유연매체의 거동해석 (Analysis of Flexible Media Behavior by Dynamic Elastica)

  • 홍성권;지중근;장용훈;박노철;박영필
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.600-605
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    • 2004
  • In many machines handling lightweight and flexible media such as magnetic tape drives, xerographic copiers and sewing machines, the media must transit an open space. It is important to predict the static and dynamic behavior of the sheets with a high degree of reliability. The nonlinear theory of the dynamic elastica has often been used to a nonlinear dynamic deflection model. In this paper, the governing equation is derived and simulated by the finite differential method. The parametric cubic curve is applied for defining the guide shape. The dynamic contact conditions suggested by Klarbring is used to predict the direction of the flexible media according to the initial velocity and the friction coefficient. The analysis is also compared to the conventional model, showing that after contacting a $45^{\circ}$ wall, the directions of flexible media of two models are different.

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Dynamic Elastica에 의한 유연매체의 거동해석 (Analysis of Flexible Media Behavior by Dynamic Elastica)

  • 홍성권;지중근;장용훈;박노철;박영필
    • 한국소음진동공학회논문집
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    • 제15권2호
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    • pp.206-212
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    • 2005
  • In many machines handling lightweight and flexible media, such as magnetic tape drives, xerographic copiers and sewing machines, the media must transit an open space. It is important to predict the static and dynamic behavior of the sheets with a high degree of reliability. The nonlinear theory of the dynamic elastica has often been used to a nonlinear dynamic deflection model. In this paper, the governing equation is derived and simulated by the finite difference method. The parametric cubic curve is applied for defining the guide shape. The dynamic contact conditions suggested by Klarbring is used to predict the direction of the flexible media according to the initial velocity and the friction coefficient. The analysis is also compared to the conventional model, showing that after contacting a $45^{\circ}$ wall, the directions of flexible media of two models are different.

크림프를 가진 섬유 캔틸레버의 대변형의 일래스티카 해 (Elastica Solution of Large Deformation of Fiber Cantilever with Crimped Shapes)

  • 정재호;강태진
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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    • pp.102-105
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    • 2001
  • In this paper, the solution of two dimensional deflection of circular wavy elastica beam was obtained for one end clamped boundary and concentrated load condition. The beam was regarded as a linear elastic material. Wavy shape was described as a combination of half-circular arc smoothly connected each other with constant curvature of all the same magnitude and alternative sign. Also load direction was taken into account. As a result, the solution was expressed in terms of a series of integral equations. While we found the exact solutions and expressed them in terms of elliptic integrals, the recursive ignition formulae about the displacement and arc length at each segment of circular section were obtained. Algorithm of determining unknown parameters was established and the profile curve of deflected beam was shown compared with initial shape.

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Elliptic Integral Solutions of Large Deflection of Reinforcing Fiber Elastica with Circular Wavy Pattern

  • Jung, Jae-Ho;Lee, Kyung-Woo;Kang, Tae-Jin
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2001년도 추계학술발표대회 논문집
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    • pp.163-169
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    • 2001
  • The solution of two-dimensional deflection of circular wavy reinforcing fiber elastics was obtained for one end clamped boundary under concentrated load condition. The fiber was regarded as a linear elastic material. Wavy shape was described as a combination of half-circular arc smoothly connected each other with constant curvature of all the same magnitude and alternative sign. Also load direction was taken into account. As a result, the solution was expressed in terms of a series of elliptic integrals. These elliptic integrals had two different transformed parameters involved with load value and initial radius of curvature. While we found the exact solutions and expressed them in terms of elliptic integrals, the recursive ignition formulae about the displacement and arc length at each segment of circular section were obtained. Algorithm of determining unknown parameters was established and the profile curve of deflected beam was shown in comparison with initial shape.

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

  • 이병구;오상진;모정만;진태기
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1996년도 가을 학술발표회 논문집
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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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