Yazarlar

  • MakaleYalnız künye2023Scopus SJRQ2
    Free vibration and buckling of functionally graded porous beams using analytical, finite element, and artificial neural network methods

    Turan, Muhittin; Uzun Yaylacı, Ecren; Yaylacı, Murat

    In this study, an analytical solution based on the first-order shear deformation theory was performed for free vibration and buckling analysis of functionally graded porous beams (FGM-P) subjected to various boundary conditions. Also, this problem is solved by using finite element (FEM) and artificial neural network (ANN) methods. Here a Ritz-based analytical solution is used, and different polynomial series functions are proposed for each boundary condition. Lagrange's principle was used while deriving the equations of motion. A power-law rule describes the variation of the beam's materials in volume. The normalized fundamental frequencies and critical buckling loads are obtained for various boundary conditions, power-law index (k), slenderness (L/h), porosity coefficient (e), and porosity distribution (FGM-P1, FGM-P2). The polynomial series functions used in this study were verified with the literature, and the numerical results obtained were compared with FEM and ANN. The results obtained are quite compatible with each other.

    AtıfScopus140WoS136OpenAlex101
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  • MakaleAçık Erişim2021Scopus SJRQ2
    Free vibration and buckling analysis of functionally graded sandwich beams by Navier's method; [Fonksiyonel derecelendirilmiş sandviç kirişlerin Navier yöntemiyle serbest titreşim ve burkulma analizi]

    Turan, Muhittin; Kahya, Volkan

    In this study, free vibration and buckling analyses of functionally graded (FGM) sandwich beams is investigated by Navier's method. Displacement field is defined according to the first order shear deformation theory, and the equations of motion are derived by the Lagrange's principle. Volumetric ceramic ratio is defined by a power-law rule. In the analytical solution, different trigonometric series functions are used for each end conditions considered. Two cases of functionally graded sandwich beams are considered: a) Homogeneous ceramic core and FGM faces (Type A), and b) FGM core and homogeneous faces (Type B). Natural frequencies and buckling loads are obtained for different boundary conditions, power-law indices and slenderness. Numerical results are compared with the available literature, and a good agreement are obtained between the results.

    AtıfScopus24WoS21OpenAlex16TR Dizin7
    ScopusWeb of ScienceTR Dizinİncele
  • MakaleYalnız künye2018Scopus SJRQ1
    Vibration and stability analysis of functionally graded sandwich beams by a multi-layer finite element

    Kahya, Volkan; Turan, Muhittin

    This paper presents a finite element model based on the first-order shear deformation theory for free vibration and buckling analyses of functionally graded (FG) sandwich beams. The present element has 3 N + 7 degrees-of-freedom for an N-layer beam. Lagrange's equations are employed for derivation of the equations of motion. Two types of FG sandwich beams are considered: (a) Type A with FG faces and homogeneous ceramic core, and (b) Type B with homogeneous ceramic and metal faces and FG core. Natural frequencies and buckling loads are calculated numerically for different boundary conditions, power-law indices, and span-to-height ratios. Accuracy of the present element is demonstrated by comparisons with the results available, and discussions are made on the results given in graphs and tables for the sandwich beams considered.

    AtıfScopus89WoS81OpenAlex81
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2014Scopus SJRQ3
    Free vibration analysis of a laminated composite beam with various boundary conditions

    Balci, Murat; Nalbant, Mustafa Oǧuz; Kara, Ercan; Gündoǧdu, Ömer

    This study presents a free vibration analysis of a laminated composite beam, based on the Euler-Bernoulli beam theory. A numerical model of the laminated composite beam was obtained for various boundary conditions based on different length-to-thickness ratios for a number of layers, using the finite element method. A planar beam bending element with two nodes, each having two degrees of freedom, was chosen according to Euler-Bernoulli beam theory. The natural frequencies of the laminated composite beam were obtained for each case, and presented in such a way as to display the effect of these changes on the natural frequencies. Eight natural frequencies of clamped-free, clamped-clamped (CC) and simple-simple (SS) composite beams were first obtained for different length-to-thickness ratios (Lx /h), numbers of layers, layer angles and for their different positions. It can be seen that natural frequencies decrease for all modes with increasing length-to-thickness ratio in all cases.

    AtıfScopus19WoS11OpenAlex15
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2013
    DETERMINATION OF PHYSICAL PROPERTIES OF LAMINATED COMPOSITE BEAM VIA THE INVERSE VIBRATION PROBLEM METHOD

    Balci, Murat; Gündogdu, Omer

    In this study, some physical properties of a laminated composite beam were estimated by using the inverse vibration problem method. Laminated composite plate was modeled and simulated to obtain vibration responses for different length-to-thickness ratios in ANSYS. A numerical model of the laminated composite beam with unknown parameters was also developed using a two-dimensional finite element model by utilizing the Euler-Bernoulli beam theory. Then, these two models were embedded into the optimization program to form the objective function to be minimized using genetic algorithms. After minimizing the squared difference of the natural frequencies from these two models, the unknown parameters of the laminated composite beam were found. It is observed in this study that the Euler-Bernoulli beam theory suppositions approximated the real results with a rate of %0.026 error as the thickness of the beam got thinner. The estimated values were finally compared with the expected values and a very good correspondence was observed.

    AtıfWoS3OpenAlex8
    Web of Scienceİncele