Yazarlar

  • MakaleYalnız künye2010Scopus SJRQ1
    Multiobjective optimization of angle-ply laminated plates for maximum buckling load

    Topal, Umut; Uzman, Ümit

    This paper deals with multiobjective optimization of symmetrically angle-ply square laminated plates subjected to biaxial compressive and uniform thermal loads. The design objective is the maximization of the buckling load for weighted sum of the biaxial compressive and thermal loads. The design variable is the fiber orientations in the layers. The performance index is formulated as the weighted sum of individual objectives in order to obtain optimal solutions of the design problem. The first-order shear deformation theory (FSDT) is used in the mathematical formulation of buckling analysis of laminated plates. The modified feasible direction (MFD) method is used for optimization routine. For this purpose, a program based on FORTRAN is used. Finally, the effect of different weighting factors, number of layers, aspect ratios, load ratios and boundary conditions on the optimal design is investigated.

    AtıfScopus24WoS22OpenAlex26
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2010
    Effect of rectangular/circular cutouts on thermal buckling load optimization of angle-ply laminated thin plates

    Topal, Umut; Uzman, Ümit

    This paper deals with thermal buckling load optimization of symmetrically laminated angle-ply thin plates with centrally located different cutouts subjected to a uniform temperature load rise. The optimum results are given for maximum buckling temperature and the fibre orientation is adopted as design variable. The results are obtained for the various cutout geometries such as rectangle and circle. The modified feasible direction (MFD) method is used for the optimization routine. Therefore a program based on FORTRAN is used. Finally, the effects of cutout areas, plate aspect ratios and boundary conditions on the optimum results are demonstrated.

    AtıfScopus6WoS4OpenAlex5
    ScopusWeb of Scienceİncele
  • MakaleYalnız künye2008Scopus SJRQ1
    Strength optimization of laminated composite plates

    Topal, Umut; Uzman, Ümit

    A procedure to select the optimum fiber orientations and determine the maximum load-bearing capacity of the simply supported symmetrically laminated plates combined the bidirectional tension loads and bending moments is described. The fiber orientation is considered a design variable. The optimization problem consists of two stages. The objective of the first stage is to maximize the strength of the laminated plates by determining the fiber orientations optimally while the objective of the second stage is to maximize each of the bidirectional tension loads and bending moments subject to the Tsai-Wu failure criterion for the optimum fiber orientations obtained from the first stage. The modified feasible direction method (MFD) is used as an optimization procedure. Therefore, a FORTRAN program is used for the finite element analysis and optimization routine. Also, the optimum fiber orientations are obtained using the golden section (GS) method to compare the results. Finally, the effect of the different plate aspect ratio, width-to thickness ratio, the uncertainties in the material properties and the uncertainties in the fiber orientations on the optimum results is investigated and the results are compared.

    AtıfScopus9OpenAlex9
    Scopusİncele
  • MakaleYalnız künye2008Scopus SJRQ1
    Thermal buckling load optimization of laminated composite plates

    Topal, U.; Uzman, Ü.

    In this study, the applicability of the Modified Feasible Direction (MFD) method on the thermal buckling optimization of laminated plates subjected to uniformly distributed temperature load is investigated. The objective function is to maximize the critical temperature capacity of laminated plates and the fiber orientation is considered as design variable. The first-order shear deformation theory is used in the mathematical formulation. For this purpose, a program based on FORTRAN is used for the optimization of laminated plates. Finally, the effect of aspect ratio, antisymmetric lay-up, boundary condition, material anisotropy, ratio of coefficients of thermal expansion, and hybrid laminates on the results is investigated and the results are compared.

    AtıfScopus67OpenAlex67
    Scopusİncele