• Title/Summary/Keyword: elastic rectangular plate

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Bending of FGM rectangular plates resting on non-uniform elastic foundations in thermal environment using an accurate theory

  • Bouderba, Bachir
    • Steel and Composite Structures
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    • v.27 no.3
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    • pp.311-325
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    • 2018
  • This article presents the bending analysis of FGM rectangular plates resting on non-uniform elastic foundations in thermal environment. Theoretical formulations are based on a recently developed refined shear deformation theory. The displacement field of the present theory is chosen based on nonlinear variations in the in-plane displacements through the thickness of the plate. The present theory satisfies the free transverse shear stress conditions on the top and bottom surfaces of the plate without using shear correction factor. Unlike the conventional trigonometric shear deformation theory, the present refined shear deformation theory contains only four unknowns as against five in case of other shear deformation theories. The material properties of the functionally graded plates are assumed to vary continuously through the thickness, according to a simple power law distribution of the volume fraction of the constituents. The elastic foundation is modeled as non-uniform foundation. The results of the shear deformation theories are compared together. Numerical examples cover the effects of the gradient index, plate aspect ratio, side-to-thickness ratio and elastic foundation parameters on the thermo-mechanical behavior of functionally graded plates. Numerical results show that the present theory can archive accuracy comparable to the existing higher order shear deformation theories that contain more number of unknowns.

Electro-elastic analysis of a sandwich thick plate considering FG core and composite piezoelectric layers on Pasternak foundation using TSDT

  • Mohammadimehr, Mehdi;Rostami, Rasoul;Arefi, Mohammad
    • Steel and Composite Structures
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    • v.20 no.3
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    • pp.513-543
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    • 2016
  • Third order shear deformation theory is used to evaluate electro-elastic solution of a sandwich plate with considering functionally graded (FG) core and composite face sheets made of piezoelectric layers. The plate is resting on the Pasternak foundation and subjected to normal pressure. Short circuited condition is applied on the top and bottom of piezoelectric layers. The governing differential equations of the system can be derived using Hamilton's principle and Maxwell's equation. The Navier's type solution for a sandwich rectangular thick plate with all edges simply supported is used. The numerical results are presented in terms of varying the parameters of the problem such as two elastic foundation parameters, thickness ratio ($h_p/2h$), and power law index on the dimensionless deflection, critical buckling load, electric potential function, and the natural frequency of sandwich rectangular thick plate. The results show that the dimensionless natural frequency and critical buckling load diminish with an increase in the power law index, and vice versa for dimensionless deflection and electrical potential function, because of the sandwich thick plate with considering FG core becomes more flexible; while these results are reverse for thickness ratio.

Thermal postbuckling of imperfect Reissner-Mindlin plates with two free side edges and resting on elastic foundations

  • Shen, Hui-Shen
    • Structural Engineering and Mechanics
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    • v.6 no.6
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    • pp.643-658
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    • 1998
  • A thermal postbuckling analysis is presented for a moderately thick rectangular plate subjected to uniform or nonuniform tent-like temperature loading and resting on an elastic foundation. The plate is assumed to be simply supported on its two opposite edges and the two side edges remain free. The initial geometrical imperfection of the plate is taken into account. The formulation are based on the Reissner-Mindlin plate theory considering the first order shear deformation effect, and including plate-foundation interaction and thermal effects. The analysis uses a mixed Galerkin-perturbation technique to determine the thermal buckling loads and postbuckling equilibrium paths. Numerical examples are presented that relate to the performances of perfect and imperfect, moderately thick plates resting on Pasternak-type or softening nonlinear elastic foundations from which results for Winker elastic foundations follow as a limiting case. Typical results are presented in dimensionless graphical form.

Bending and buckling of a rectangular porous plate

  • Magnucki, K.;Malinowski, M.;Kasprzak, J.
    • Steel and Composite Structures
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    • v.6 no.4
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    • pp.319-333
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    • 2006
  • A rectangular plate made of a porous material is the subject of the work. Its mechanical properties vary continuously on the thickness of a plate. A mathematical model of this plate, which bases on nonlinear displacement functions taking into account shearing deformations, is presented. The assumed displacement field, linear geometrical and physical relationships permit to describe the total potential energy of a plate. Using the principle of stationarity of the total potential energy the set of five equilibrium equations for transversely and in-plane loaded plates is obtained. The derived equations are used for solving a problem of a bending simply supported plate loaded with transverse pressure. Moreover, the critical load of a bi-axially in-plane compressed plate is found. In both cases influence of parameters on obtained solutions such as a porosity coefficient or thickness ratio is analysed. In order to compare analytical results a finite element model of a porous plate is built using system ANSYS. Obtained numerical results are in agreement with analytical ones.

Stability Analysis of Rectangular Plate with Concentrated Mass (집중질량을 갖는 장방형판의 안정해석)

  • 김일중;오숙경;이용수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.805-809
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    • 2004
  • This paper is for the vibration analysis of thick plate with concentrated mass on a inhomogeneous pasternak foundation. The vibration of rectangular plate on the inhomogeneous pasternak foundation, natural frequency of this plate with Concentrated Mass are calculated A thick rectangular plate resting on a inhomogeneous pasternak foundation is isotropic, homogeneous and composite with linearly elastic material. In order to analysis 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 WFP1 and WFP2 respectively. The value of WFP1 and WFP2 can be changed as 10, 10$^3$ and the value of SFP(shear foundation parameter) also be changed 5, 15 respectively.

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Flexural Vibration of a Rectangular Plate with Orthotropically and Harmonically Varying Material Properties (재질분포가 직교이방 조화함수로 변하는 사각 평판의 굽힘 진동 해석)

  • 김진오;문병환
    • Journal of KSNVE
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    • v.11 no.2
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    • pp.323-328
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    • 2001
  • The paper describes a theoretical study on the flexural vibration of an elastic rectangular plate with periodically nonuniform material properties. The approximate solution of the natural frequency and mode shape has been obtained using the perturbation technique for sinusoidal modulation of the flexural rigidity and mass density. It has been shown that distributed modes exist in the plate which Is a two-dimensional model of the flat panel speaker.

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Thermomechanical postbuckling of imperfect moderately thick plates on two-parameter elastic foundations

  • Shen, Hui-Shen
    • Structural Engineering and Mechanics
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    • v.4 no.2
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    • pp.149-162
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    • 1996
  • A postbuckling analysis is presented for a simply supported, moderately thick rectangular plate subjected to combined axial compression and uniform temperature loading and resting on a two-parameter elastic foundation. The two cases of thermal postbuckling of initially compressed plates and of compressive postbuckling of initially heated plates are considered. The initial geometrical imperfection of the plate is taken into account. The formulations are based on the Reissner-Mindlin plate theory considering the first order shear deformation effect, and including the plate-foundation interaction and thermal effect. The analysis uses a deflection-type perturbation technique to determine the buckling loads and postbuckling equilibrium paths. Numerical examples cover the performances of perfect and imperfect, moderately thick plates resting on Winkler or Pasternak-type elastic foundations. Typical results are presented in dimensionless graphical form.

The Vibration of an Elastic Rectangular Plate in a Fluid (직사각형판(直四角形板)의 접수진동(接水振動))

  • Keuck-Chun,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.13 no.4
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    • pp.1-10
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    • 1976
  • It is a well-known phenomenon that, in the case of vibrations of an elastic body in a fluid such as water, the presence of the surrounding fluid has the effect of lowering the natural frequencies of the vibration as compared with those in air or vacuum on account of the increased inertia, i.e. added mass. In this report, defining the mass increase factor as the ratio of added mass to vibration mass of the body in air, the author investigated the mass increased factor of an elastic plate vibrating in the fluid. It is assumed that the edges of the plate are simply supported, and that the surrounding fluid is an infinite ideal one. For the problem formulation the elliptical cylindrical coordinate system is adopted, so that a rectangular plate may be represented by a sheet degenerated from an elliptical cylinder. By virtue of the coordinate system adopted, plates which are chordwisely finite and lengthwisely contineous could directly be treated, but plates which are chordwisely finite in both directions could not be treated directly. For the latter, hence, plates which are chordwisely finite and lengthwisely semi-finite are investigated as an appropriate approximation. Some examples of the mass increase factor are numerically calculated for the fundamental mode and modes of zero or one nodal line in each direction with the range of the aspect ratio from 1 to 10 or more.

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Dynamic stability of a metal foam rectangular plate

  • Debowski, D.;Magnucki, K.;Malinowski, M.
    • Steel and Composite Structures
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    • v.10 no.2
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    • pp.151-168
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    • 2010
  • The subject of the paper is an isotropic metal foam rectangular plate. Mechanical properties of metal foam vary continuously through plate of the thickness. A nonlinear hypothesis of deformation of plane cross section is formulated. The system of partial differential equations of the plate motion is derived on the basis of the Hamilton's principle. The system of equations is analytically solved by the Bubnov-Galerkin method. Numerical investigations of dynamic stability for family rectangular plates with respect analytical solution are performed. Moreover, FEM analysis and theirs comparison with results of numerical-analytical calculations are presented in figures.

Natural Frequency of a Rectangular Plate on Non-homogeneous Elastic Foundations (비균질 탄성 기초위에 놓여있는 직사각형 평판의 고유 진동수)

  • Hwang, Ju-Ik;Kim, Yong-Cheol;Lee, Taek-Sun
    • Journal of Ocean Engineering and Technology
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    • v.3 no.2
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    • pp.570-570
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    • 1989
  • The natural frequencies of a rectangular plate on non-homogeneous elastic foundations were obtained by using the Ritz method and Galerkin method. The results of both methods using the different type of trial functions were also compared. Furthermore, the effects of the variation of boundary conditions, the stiffness of the foundation spring, the dimension ratio of the plate were investigated. As a result, the Galerkin method can be used to obtain the accurate solution and can be effectively used to design the foundation bed.