• Title/Summary/Keyword: discrete singular convolution

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Discrete singular convolution for buckling analyses of plates and columns

  • Civalek, Omer;Yavas, Altug
    • Structural Engineering and Mechanics
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    • v.29 no.3
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    • pp.279-288
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    • 2008
  • In the present study, the discrete singular convolution (DSC) method is developed for buckling analysis of columns and thin plates having different geometries. Regularized Shannon's delta (RSD) kernel is selected as singular convolution to illustrate the present algorithm. In the proposed approach, the derivatives in both the governing equations and the boundary conditions are discretized by the method of DSC. The results obtained by DSC method were compared with those obtained by the other numerical and analytical methods.

Frequency analysis of moderately thick uniform isotropic annular plates by discrete singular convolution method

  • Civalek, Omer;Ersoy, Hakan
    • Structural Engineering and Mechanics
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    • v.29 no.4
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    • pp.411-422
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    • 2008
  • In the present study, free vibration analysis of thick annular plates is analyzed by discrete singular convolution method. The Mindlin plate theory is employed. The material is isotropic, homogeneous and obeys Hook's law. In this paper, discrete singular convolution method is used for discretization of equations of motion. Axisymmetric frequency values are presented illustrating the effect of radius ratio and thickness to radius ratio of the annular plate. The influence of boundary conditions on the frequency characteristics is also discussed. Comparing results with those in the literature validates the present analysis. It is shown that the obtained results are very accurate by this approach.

Free vibration analysis of composite conical shells using the discrete singular convolution algorithm

  • Civalek, Omer
    • Steel and Composite Structures
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    • v.6 no.4
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    • pp.353-366
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    • 2006
  • The discrete singular convolution (DSC) algorithm for determining the frequencies of the free vibration of single isotropic and orthotropic laminated conical shells is developed by using a numerical solution of the governing differential equations of motion based on Love's first approximation thin shell theory. By applying the discrete singular convolution method, the free vibration equations of motion of the composite laminated conical shell are transformed to a set of algebraic equations. Convergence and comparison studies are carried out to check the validity and accuracy of the DSC method. The obtained results are in excellent agreement with those in the literature.

Discrete singular convolution method for bending analysis of Reissner/Mindlin plates using geometric transformation

  • Civalek, Omer;Emsen, Engin
    • Steel and Composite Structures
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    • v.9 no.1
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    • pp.59-75
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    • 2009
  • In this study, a simple approach for bending analysis of Reissner-Mindlin plates is presented using the four-node quadrilateral domain transformation based on discrete singular convolution. In the proposed approach, irregular physical domain is transformed into a rectangular domain by using the geometric coordinate transformation. The DSC procedures are then applied to discrete the governing equations and boundary conditions. The accuracy of the proposed method is verified by comparison with known solutions obtained by other numerical or analytical methods. Results for Reissner-Mindlin plates show a satisfactory agreement with the analytical and numerical solutions.

Free vibration of circular and annular membranes with varying density by the method of discrete singular convolution

  • Ersoy, Hakan;Ozpolat, Lutfiye;Civalek, Omer
    • Structural Engineering and Mechanics
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    • v.32 no.5
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    • pp.621-634
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    • 2009
  • A numerical method is developed to investigate the effects of some geometric parameters and density variation on frequency characteristics of the circular and annular membranes with varying density. The discrete singular convolution method based on regularized Shannon's delta kernel is applied to obtain the frequency parameter. The obtained results have been compared with the analytical and numerical results of other researchers, which showed well agreement.

Vibration analysis of plates with curvilinear quadrilateral domains by discrete singular convolution method

  • Civalek, Omer;Ozturk, Baki
    • Structural Engineering and Mechanics
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    • v.36 no.3
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    • pp.279-299
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    • 2010
  • A methodology on application of the discrete singular convolution (DSC) technique to the free vibration analysis of thin plates with curvilinear quadrilateral platforms is developed. In the proposed approach, irregular physical domain is transformed into a rectangular domain by using geometric coordinate transformation. The DSC procedures are then applied to discretization of the transformed set of governing equations and boundary conditions. For demonstration of the accuracy and convergence of the method, some numerical examples are provided on plates with different geometry such as elliptic, trapezoidal having straight and parabolic sides, sectorial, annular sectorial, and plates with four curved edges. The results obtained by the DSC method are compared with those obtained by other numerical and analytical methods. The method is suitable for the problem considered due to its generality, simplicity, and potential for further development.

Stability and non-stationary vibration analysis of beams subjected to periodic axial forces using discrete singular convolution

  • Song, Zhiwei;Li, Wei;Liu, Guirong
    • Structural Engineering and Mechanics
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    • v.44 no.4
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    • pp.487-499
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    • 2012
  • Dynamic instability of beams subjected to periodic axial forces is studied using the discrete singular convolution (DSC) method with the regularized Shannon's delta kernel. The principal regions of dynamic instability under different boundary conditions are examined in detail, and the non-stationary vibrations near the stability-instability critical regions have been investigated. It is found that the results obtained by using the DSC method are consistent with the analytical solutions, which shows that the DSC algorithm is suitable for the problems considered in this study. It was found that there is a narrow region of beat vibration existed in the vicinity of one side (${\theta}/{\Omega}$ > 1) of the boundaries of the instable region for each condition.

Nonlinear vibration analysis of laminated plates resting on nonlinear two-parameters elastic foundations

  • Akgoz, Bekir;Civalek, Omer
    • Steel and Composite Structures
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    • v.11 no.5
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    • pp.403-421
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    • 2011
  • In the present manuscript, geometrically nonlinear free vibration analysis of thin laminated plates resting on non-linear elastic foundations is investigated. Winkler-Pasternak type foundation model is used. Governing equations of motions are obtained using the von Karman type nonlinear theory. The method of discrete singular convolution is used to obtain the discretised equations of motion of plates. The effects of plate geometry, boundary conditions, material properties and foundation parameters on nonlinear vibration behavior of plates are presented.

Vibration of angle-ply laminated composite circular and annular plates

  • Mercan, Kadir;Ebrahimi, Farzad;Civalek, Omer
    • Steel and Composite Structures
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    • v.34 no.1
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    • pp.141-154
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    • 2020
  • In the present paper, free vibration analysis of angle-ply laminated composite annular and circular plates is performed by numerical methods. First-order shear deformation plate theory is used for kinematic relations. The related governing equations of motion are discretized via differential quadrature and discrete singular convolution methods. Frequency values are obtained for different lamina scheme, thickness-to-radius ratio, and mode numbers. The advantages and accuracy of these two methods are also tested in detail.

Free vibration analysis of tapered beam-column with pinned ends embedded in Winkler-Pasternak elastic foundation

  • Civalek, Omer;Ozturk, Baki
    • Geomechanics and Engineering
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    • v.2 no.1
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    • pp.45-56
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    • 2010
  • The current study presents a mathematical model and numerical method for free vibration of tapered piles embedded in two-parameter elastic foundations. The method of Discrete Singular Convolution (DSC) is used for numerical simulation. Bernoulli-Euler beam theory is considered. Various numerical applications demonstrate the validity and applicability of the proposed method for free vibration analysis. The results prove that the proposed method is quite easy to implement, accurate and highly efficient for free vibration analysis of tapered beam-columns embedded in Winkler- Pasternak elastic foundations.