• Title/Summary/Keyword: 변단면 기둥

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An Experimental Study on the Flexural Behavior of Reinforced Concrete Columns Strengthened with Wire Rope and T-Shape Steel Plate units (와이어로프와 T형 플레이트에 의해 보강된 RC 기둥의 휨 거동에 대한 실험적 연구)

  • Sim, Jae-Il;Yang, Keun-Hyeok;Oh, Sung-Jin;Byun, Hang-Yong
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.153-156
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    • 2008
  • The objective of the present study is to evaluate the flexural behavior of reinforced concrete columns externally strengthened with wire rope and T-shape steel plate units. Three strengened columns and a control unstrengthened column were tested under cyclic lateral load simultaneously subjected to a constant axial load. All columns had same section size, and the arrangement of longitudinal reinforcement and internal hoop. The spacing of wire rope range from 40 ${\sim}$ 80mm, which corresponds from 1.0 ${\sim}$ 0.5, respectively, times the minium amount of hoop specified in seismic design of ACI 318-05. Test results showed that the proposed unbonded-type strengthening procedure is very effective for improving the flexural ductility of reinforced concrete columns.

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Effects of Shear Deformations on Buckling Loads of Tapered Columns with Both Clamped Ends (전단변형이 양단고정 변단면 기둥의 좌굴하중에 미치는 영향)

  • 이병구;이태은;안대순
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2000.04b
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    • pp.92-99
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    • 2000
  • The nondimensional differential equations governing the buckling loads of tapered columns with both clamped ends and its boundary conditions are derived, in which the effects of shear deformations are included. These equations are solved numerically using a numerical integration technique and a bracketing method to obtain the buckling loads of columns. Four types of cross-sectional shape are considered in the numerical examples. The parametric studies of shear deformation effects on the buckling loads such as cross-sectional shape factor, shear coefficient, ratio of modulus of elasticity, slenderness ratio and section ratio are reported in tables and figures.

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Elastic Critical Load of Non-symmetrically Tapered Columns by Numerical Method (수치해석법에 의한 비대칭 변단면 기둥의 탄성 임계하중)

  • 신세욱;김선혜;이수곤
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.04a
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    • pp.11-18
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    • 1999
  • For the proper design of a slender compression member, the exact determination of the elastic critical load is crucial, In the cases of non-prismatic compression members, the determinations of the elastic critical load cannot be usually expressed in closed forms. h this paper, the non-symmetrically tapered compression members with arbitrary boundary conditions me analysed by using the finite element method to determine the elastic critical load. The main parameters considered in the numerical analysis are the In Parameter, $\alpha$ and the sectional property parameter, m. To generaliza the unmerical analysis, of the computed results for each sectional parameter, m are presented in algebraic equations, which agrees fairy well with those by F.E.M in most cases.

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Dynamic Stability Analysis of Tapered Beck Columns (변단면 Beck 기둥의 동적안정 해석)

  • Lee Byoung-Koo;Lee Tae-Eun;Kang Hee-Jong;Kim Gwon-Sik
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.949-954
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    • 2006
  • The purpose of this paper is to investigate the stability of tapered columns with clamped one end and carrying a tip mass of rotatory inertia with translational elastic support at the other end. The linearly tapered columns with the solid rectangular cross-section is adopted as the column taper. The differential equation governing free vibrations of such Beck columns is derived using the Bernoulli-Euler beam theory. Both the divergence and flutter critical loads are calculated from the load-frequency curves which are obtained by solving the differential equation. The critical loads are presented as functions of various non-dimensional system parameters: the taper type, the subtangential parameter, mass ratio and spring stiffness.

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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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Free Vibrations and First Critical Loads of Tapered Columns (변단면 기둥의 자유진동 및 최소임계하중 해석)

  • 이병구;오상진;모정만;김헌상
    • Journal of KSNVE
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    • v.2 no.3
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    • pp.203-211
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    • 1992
  • The main purpose of this paper is to present both the natural frequencies and the first critical loads of tapered columns. The ordinary differential equation governing the free vibration for tapered columns under compressive axial force is derived. Three kinds of cross sectional shape are considered in the governing equation. The Runge-Kutta method and determinant search method are used to perform the integration of the differential equation and to determine the natural frequencies, respectively. Additionally, the bisection method is used to determine the critical loads. In numerical examples, the effects of compressive axial force on the natural frequencies of tapered columns are investigated varying the end conditions. The first critical loads of tapered columns are determined on the basis of dynamic concepts. The first critical loads of tapered columns are determined on the basis of dynamic concept. The effects of cross sectional shapes are shown and some typical mode shapes are also presented.

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Effective length factors for the framed columns with variable stiffness (골조구성 변단면 기둥의 유효길이 계수)

  • 이수곤;김순철;오금열
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.10a
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    • pp.175-182
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    • 2001
  • Effective length factor approach for framed column design has long played an important design-aid role. This approach, however, is effective only when the columns are in the form of prismatic or uniform cross sections. Structural engineers who have to design or analyse framed columns with variable cross sections need some means to do their job. By using the finite element method, the stability analysis of the isolated compression members with variable cross sections and that of the framed columns are performed. The parameters considered in the stability analysis are taper and sectional property parameters of the columns, the second moment of inertia ratio of beam to column, and beam span to column height ratio. On the basis of the stability analysis results, effective length factor formulas for the columns with variable sections are derived.

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Behavior of Tapered Columns with Initial Imperfection (Initial Imperfection을 갖는 변단면 기둥의 거동 해석)

  • 이병구;모정만
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.04a
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    • pp.19-26
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    • 1996
  • The main purpose of this paper is to investigate a more accurate behavior analysis of tapered column with initial imperfection. The nonlinear differential equations governing the deflected shapes of the tapered column with initial imperfection are derived by large deflection theory and solved numerically using the Runge-Kutta method and Regula-Falsi method. Three kinds of cross-sectional shape with simply supported end constraint are considered in numerical examples. The load versus displacement curves including the left and right end rotations are presented in figures. The effect of cross-sectional shapes on deflected shape is analyzed, and the deflected shapes of column for several initial imperfections are shown in figure.

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Effective Length Factors of Framed Columns with Sinusoidally Tapered Sections (정현상 변단면 기둥의 유효길이 계수)

  • 박재영;송상용;김순철;이수곤
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.243-250
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    • 2003
  • A method for the determination of effective length factors of the framed columns with sinusoidally tapered sections is proposed. In the study, the stability analysis of the single story-two equal bay, frame with tapered columns is performed first by finite element method. The changes of the critical load coefficients of frames are reprersented by algebraic equations of the analysis parameters. The effective length factor formula is expressed in terms of proposed algebraic equation. The effective length factors for the prismatic columns (α=0.0) estimated by the proposed method coincide fairly well with those determined by the analytical method.

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Proposal of a New Design Method of the Pile-Bent Structure Considering Plastic Hinge (단일 현장타설말뚝의 소성힌지를 고려한 최적설계법 제안)

  • Ahn, Sang-Yong;Jeong, Sang-Seom;Kim, Jae-Young
    • Journal of the Korean Geotechnical Society
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    • v.27 no.2
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    • pp.91-101
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    • 2011
  • In this study, a new design method of Pile-Bent structure considering plastic hinge was proposed on the basis of the beam-column model. To obtain the detailed informations, the optimized cross-section ratio between column and pile was analyzed to induce the plastic hinge at the joint section between the pile and column. Base on this study, the optimized diameter ratio of pile and column can be obtained below the inflection point of the bi-linear curve depending on the relations between column-pile diameter ratio ($D_c/D_p$) and normalized lateral cracking load ratio ($F/F_{Dc=Dp}$). Moreover, through comparisons with field cases to find out in-depth limit in which minimum concrete-steel ratio could be applied, in-depth limits ($L_{As=0.4%}$) normalized by the pile length ($L_p$) proportionally decrease as the pile length ($L_p/D_p$)increases up to $L_p/D_p=17.5$, and beyond that in-depth limit converges to a constant value (${\simeq}0.3$).