• Title/Summary/Keyword: Pasternak

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Free Vibration Analysis of Thin Plate on Inhomogeneous Pasternak Foundation (비균질 Pasternak 지반위에 얹혀진 박판의 자유진동 해석)

  • Kim, Il-Jung;Lee, Young-Soo;Oh, Soog-Kyoung;Lee, Hoy-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.395.2-395
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    • 2002
  • Recently, as size of building structure becomes larger, mat area of building structure is supported on Inhomogeneous foundation. The equipment machineries in building are mostly on basement story. The slab of the lowest basement story with equipment machineries is considerded as concentrated masses on plate supported on foundation. In this paper. vibration analysis of rectangular thin plate is done by use of rectangular finite element with 4 nodes. (omitted)

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Free Vibration Analysis of Thin Plate on Inhomogeneous Pasternak Foundation (비균질 Pasternak 지반 위에 놓인 박판의 자유진동 해석)

  • Lee, Yong-Soo;Oh, Soog-Kyoung;Lee, Hoy-Jin;Kim, Il-Jung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.982-987
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    • 2002
  • Recently, as size of building structure becomes larger, mat area of building structure is supported on Inhomogeneous foundation. The equipment machineries in building are mostly on basement story. The slab of the lowest basement story with equipment machineries is considered as plate supported on foundation with concentrated masses. In this paper, vibration analysis of rectangular thin plate is done by use of rectangular finite element with 4 nodes. The solution of this paper are compared with existing solution and natural frequencies of thin plates, with concented mass, on inhomogeneous Pasternak foundation are calculated

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Vibration attenuation in periodic composite Timoshenko beams on Pasternak foundation

  • Xiang, Hong-Jun;Shi, Zhi-Fei
    • Structural Engineering and Mechanics
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    • v.40 no.3
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    • pp.373-392
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    • 2011
  • Periodic and quasi-periodic Timoshenko beams on Pasternak foundation are investigated using the differential quadrature method. Not only band gaps in the beams but also the dynamic response of them is analyzed. Numerical results show that vibration in periodic beams can be dramatically attenuated when the exciting frequency falls into band gaps. Different from the band structures of periodic beams without foundation, the so-called critical frequency was found because of the Pasternak foundation. Its physical meaning was explained in detail and a useful formula was given to calculate the critical frequency. Additionally, a comprehensive parameter study is conducted to highlight the influence of foundation modulus on the band gaps.

Stability Analysis of Stiffened Plates on Elastic Foundations (탄성지반으로 지지된 보강판의 안정해석)

  • Lee, Byoung-Koo;Lee, Yong-Soo;Oh, Soog-Kyoung;Lee, Tae-Eun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.12
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    • pp.947-955
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    • 2003
  • This research analyzes the dynamic stability of stiffened plates on elastic foundations using the finite element method. For analyzing the stiffened plates, both the Mindlin plate theory and Timoshenko beam-column theory were applied. In application of the finite element method, 8-nodes serendipity element system and 3-nodes finite element system were used for plate and beam elements, respectively Elastic foundations were modeled as the Pasternak foundations in which the continuity effect of foundation is considered. In order to verify the theory of this study, solutions obtained by this analysis were compared with the classical solutions in open literature and experimental solutions. The dynamic stability legions of stiffened plates on Pasternak foundations were determined according to changes of in-plane stresses, foundation parameters and dimensions of stiffener.

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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Effect of visco-Pasternak foundation on thermo-mechanical bending response of anisotropic thick laminated composite plates

  • Fatima Bounouara;Mohamed Sadoun;Mahmoud Mohamed Selim Saleh;Abdelbaki Chikh;Abdelmoumen Anis Bousahla;Abdelhakim Kaci;Fouad Bourada;Abdeldjebbar Tounsi;Abdelouahed Tounsi
    • Steel and Composite Structures
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    • v.47 no.6
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    • pp.693-707
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    • 2023
  • This article investigates the static thermo-mechanical response of anisotropic thick laminated composite plates on Visco-Pasternak foundations under various thermal load conditions (linear, non-linear, and uniform) along the transverse direction (thickness) of the plate, while keeping the mechanical load constant. The governing equations, which represent the thermo-mechanical behavior of the composite plate, are derived from the principle of virtual displacements. Using Navier's type solution, these equations are solved for the composite plate with simply supported condition. The Visco-Pasternak foundation type is included by considering the impact of the damping on the classical foundation model, which is modeled by Winkler's linear modulus and Pasternak's shear modulus. The excellent accuracy of the present solution is confirmed by comparing the results with those available in the literature. The study investigates the impact of geometric ratios, thermal expansion coefficient ratio, damping coefficient and foundation parameters on the thermo-mechanical flexural response of the composite plate. Overall, this article provides insights into the behavior of composite plates on visco-Pasternak foundations and may be useful for designing and analyzing composite structures in practical applications.

Lowest Symmetrical and Antisymmetrical Natural Frequencies of Shallow Arches on Two-Parameter Elastic Foundations (두 개의 매개변수로 표현되는 탄성지반 위에 놓인 낮은 아치의 최저차 대칭 및 역대칭 고유진동수)

  • 오상진;서종원;이병구
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.2
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    • pp.367-377
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    • 2002
  • This paper deals with the free vibrations of shallow arches resting on elastic foundations. Foundations we assumed to follow the hypothesis proposed by Pasternak. The governing differential equation is derived for the in-plane free vibration of linearly elastic arches of uniform stiffness and constant mass per unit length. Two arch shapes with hinged-hinged and clamped-clamped end constraints we considered in analysis. The frequency equations (lowest symmetrical and antisymmetrical frequency equations) we obtained by Galerkin's method. The effects of arch rise, Winkler foundation parameter and shear foundation parameter on the lowest two natural frequencies are investigated. The effect of initial arch shapes on frequencies is also studied.

Thermo-mechanical behavior of porous FG plate resting on the Winkler-Pasternak foundation

  • Rabia, Benferhat;Tahar, Hassaine Daouadji;Abderezak, Rabahi
    • Coupled systems mechanics
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    • v.9 no.6
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    • pp.499-519
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    • 2020
  • The effect of porosity on the thermo-mechanical behavior of simply supported functionally graded plate reposed on the Winkler-Pasternak foundation is investigated analytically in the present paper using new refined hyperbolic shear deformation plate theory. Both even and uneven distribution of porosity are taken into account and the effective properties of FG plates with porosity are defined by theoretical formula with an additional term of porosity. The present formulation is based on a refined higher order shear deformation theory, which is based on four variables and it still accounts for parabolic distribution of the transverse shearing strains and stresses through the thickness of the FG plate and takes into account the various distribution shape of porosity. The elastic foundation is described by the Winkler-Pasternak model. Anew modified power-law formulation is used to describe the material properties of FGM plates in the thickness direction. The closed form solutions are obtained by using Navier technique. The present results are verified in comparison with the published ones in the literature. The results show that the dimensionless and stresses are affected by the porosity volume fraction, constituent volume fraction, and thermal load.

Buckling behavior of a single-layered graphene sheet resting on viscoelastic medium via nonlocal four-unknown integral model

  • Bellal, Moussa;Hebali, Habib;Heireche, Houari;Bousahla, Abdelmoumen Anis;Tounsi, Abdeldjebbar;Bourada, Fouad;Mahmoud, S.R.;Bedia, E.A. Adda;Tounsi, Abdelouahed
    • Steel and Composite Structures
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    • v.34 no.5
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    • pp.643-655
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    • 2020
  • In the present work, the buckling behavior of a single-layered graphene sheet (SLGS) embedded in visco-Pasternak's medium is studied using nonlocal four-unknown integral model. This model has a displacement field with integral terms which includes the effect of transverse shear deformation without using shear correction factors. The visco-Pasternak's medium is introduced by considering the damping effect to the classical foundation model which modeled by the linear Winkler's coefficient and Pasternak's (shear) foundation coefficient. The SLGS under consideration is subjected to compressive in- plane edge loads per unit length. The influences of many parameters such as nonlocal parameter, geometric ratio, the visco-Pasternak's coefficients, damping parameter, and mode numbers on the buckling response of the SLGSs are studied and discussed.