• Title/Summary/Keyword: elastic supported

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Aeroelastic forces on yawed circular cylinders: quasi-steady modeling and aerodynamic instability

  • Carassale, Luigi;Freda, Andrea;Piccardo, Giuseppe
    • Wind and Structures
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    • v.8 no.5
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    • pp.373-388
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    • 2005
  • Quasi-steady approaches have been often adopted to model wind forces on moving cylinders in cross-flow and to study instability conditions of rigid cylinders supported by visco-elastic devices. Recently, much attention has been devoted to the experimental study of inclined and/or yawed circular cylinders detecting dynamical phenomena such as galloping-like instability, but, at the present state-of-the-art, no mathematical model is able to recognize or predict satisfactorily this behaviour. The present paper presents a generalization of the quasi-steady approach for the definition of the flow-induced forces on yawed and inclined circular cylinders. The proposed model is able to replicate experimental behaviour and to predict the galloping instability observed during a series of recent wind-tunnel tests.

Buckling and Vibration Analysis of Thick Plates with Concentrated Mass (집중 질량을 갖는 후판의 좌굴 및 진동해석)

  • 김일중;오숙경;이용수
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.10a
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    • pp.467-474
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    • 2001
  • This paper is for the buckling and vibration analysis of thick plate with concentrated mass on a inhomogeneous pasternak foundation. A thick rectangular plate resting on a inhomogeneous pasternak foundation is isotropic, homogeneous and composite with linearly elastic material. In order to analyize plate which is supported on inhomogeneous pasternak foundation, the value of winkler foundation parameter(WFP) of centural and border zone of plate are chosen as Kwl and Kw2 respectively. The value of Kwl and Kw2 can be changed as 0, 10, 10 /sup 2/, 10 / sup 3/ and the value of SFP(shear foundation parameter) also be changed 0, 5, 10, 15 respectively. Finally, In this paper, buckling stress of rectangular plate on the inhomogeneous pasternak foundation, natural frequency of this plate with or without uniform in-plane axial stresses are calculated

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Spatial Stability of Monosymmetric Thin-walled Circular Arch (일축대칭 단면을 갖는 박벽 원형아치의 면외좌굴해석)

  • 김문영;민병철
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.449-456
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    • 1998
  • A consistent finite element formation and analytic solutions are presented for spatial stability of thin-walled circular arch. The total potential energy is derived by applying the principle of linearized virtual work and including second order terms of finite semitangential rotations. As a result the energy functional corresponding to the semitangential rotation is obtained, in which the elastic strain energy terms are considered restrained warping effects. We have obtained analytic solution for the lateral buckling of monosymmetric thin-walled curved beam subjected to pure bending or uniform compression and it's boundary conditions are simply supported. For finite element analysis, the two node cubic Hermitian polynomials are utilized as shape Auctions. In order to illustrate the accuracy of this study, parameter studies for lateral buckling problems of circular arch are presented and compared with available solutions and numerical results analyzed by the FEM using straight beam element.

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Natural Frequency of Elastic Supported Building Slab (탄성지지된 복합재료 상판의 고유 진동수)

  • 김덕현;이정호;박정호
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.10a
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    • pp.215-222
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    • 1997
  • A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross-sections and with arbitrary boundary conditions was developed and reported by D. H. Kim in 1974. This method has been developed for two-dimensional problems including the laminated composite plates and was proved to be very effective for the plates with arbitrary boundary conditions and irregular sections. In this paper, the result of application of this method to the subject problem is presented. This problem represents the building slabs with a kind of passive and active control devices. Any method may be used to obtain the deflection influence surfaces needed for this vibration analysis. Finite difference method is used for this purpose, in this paper. The influence of the modulus of the foundation on the natural frequency is thoroughly studied.

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Rural areas, Vibration Stability Analysis of Wall and Retaining Wall of Low-rise Masonry Buildings (농촌지역 저층 조적조 건축물의 벽체 및 옹벽의 진동 안정 해석 - 전북 정읍시 ◯◯면 농촌지역 사례를 중심으로 -)

  • Lee, Deog-Yong;Kim, Il-Jung
    • Journal of the Korean Institute of Rural Architecture
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    • v.16 no.4
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    • pp.59-66
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    • 2014
  • This paper deals with vibration of plates with concentrated mass on elastic foundation. The object of investigating natural frequencies of tapered thick plate on pasternak foundation by means of finite element method and providing kinetic design data for mat of building structures. Free vibration analysis that tapered thick plate in this paper. Finite element analysis of rectangular plate is done by use of rectangular finite element with 8-nodes. In order to analysis plate which is supported on pasternak foundation. The Winkler parameter is varied with 10, $10^2$, $10^3$ and the shear foundation parameter is 5, 10. This paper is analyzed varying thickness by taper ratio. The taper ratio is applied as 0.0, 0.25, 0.5, 0.75, 1.0. And the Concentrated Mass is applied as P1, Pc, P2 respectively.

Dynamic Test method to Determine Modulus of Elasticity of Sound Insulating Coat (현장 타설용 고분자 감쇠재의 탄성 계수를 측정하기 위한 실험 기법)

  • Yemam, Dinberu Molla;Yi, Chongku
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.92-93
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    • 2015
  • The main purpose of this paper is to present the dynamic test method developed for measuring the elastic modulus of sound insulating coat. The test setup was devised based on the theoretical natural frequency of a simply-supported beam subject to free transverse vibration. A stainless steel beam was tested and the result showed a good compliance with the standard value listed in literatures. The result indicates that the test set up can serve as a quick, economical and suitable scheme to test non self-supporting materials.

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Buckling Analysis of Thin-Walled Curved Members by Finite Element Method (유한요소법에 의한 박판곡선부채의 좌굴해석)

  • Lee, Sung Chul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.11 no.2
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    • pp.1-14
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    • 1991
  • A computer program for the linear elastic buckling anlalysis of thin walled members is developed using a 3-node triangular shell element. The element has real stiffness value for a kinematic degree of freedom associated with rotation about the surface normal at each node. The validity of the present computer program is demonstrated through the plate buckling analysis and the lateral-torsional buckling analysis of a straight beam. Then, simply supported circular arches subjected to uniform bending are analyzed and the results are compared with existing solutions.

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Response of a rectangular plate-column system on a tensionless Winkler foundation subjected to static and dynamic loads

  • Guler, K.;Celep, Z.
    • Structural Engineering and Mechanics
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    • v.21 no.6
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    • pp.699-712
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    • 2005
  • The response of a plate-column system having five-degree-of-freedom supported by an elastic foundation and subjected to static lateral load, harmonic ground motion and earthquake motion is studied. Two Winkler foundation models are assumed: a conventional model which supports compression and tension and a tensionless model which supports compression only. The governing equations of the problem are obtained, solved numerically and the results are presented in figures to demonstrate the behavior of the system for various values of the system parameters comparatively for the conventional and the tensionless Winkler foundation models.

Bending and free vibration analysis of a smart functionally graded plate

  • Bian, Z.G.;Ying, J.;Chen, W.Q.;Ding, H.J.
    • Structural Engineering and Mechanics
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    • v.23 no.1
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    • pp.97-113
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    • 2006
  • A simply supported hybrid plate consisting of top and bottom functionally graded elastic layers and an intermediate actuating or sensing homogeneous piezoelectric layer is investigated by an elasticity (piezoelasticity) method, which is based on state space formulations. The general spring layer model is adopted to consider the effect of bonding adhesives between the piezoelectric layer and the two functionally graded ones. The two functionally graded layers are inhomogeneous along the thickness direction, which are approached by laminate models. The effect of interlaminar bonding imperfections on the static bending and free vibration of the smart plate is discussed in the numerical examples.

Free vibration analysis of edge cracked symmetric functionally graded sandwich beams

  • Cunedioglu, Yusuf
    • Structural Engineering and Mechanics
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    • v.56 no.6
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    • pp.1003-1020
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    • 2015
  • In this study, free vibration analysis of an edge cracked multilayered symmetric sandwich beams made of functionally graded materials are investigated. Modelling of the cracked structure is based on the linear elastic fracture mechanics theory. Material properties of the functionally graded beams change in the thickness direction according to the power and exponential laws. To represent functionally graded symmetric sandwich beams more realistic, fifty layered beam is considered. Composition of each layer is different although each layer is isotropic and homogeneous. The considered problem is carried out within the Timoshenko first order shear deformation beam theory by using finite element method. A MATLAB code developed to calculate natural frequencies for clamped and simply supported conditions. The obtained results are compared with published studies and excellent agreement is observed. In the study, the effects of crack location, depth of the crack, power law index and slenderness ratio on the natural frequencies are investigated.