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Multiobjective optimum design of laminated composite annular sector plates
Umut Topal 국제구조공학회 2013 Steel and Composite Structures, An International J Vol.14 No.2
This paper deals with multiobjective optimization of symmetrically laminated composite angleply annular sector plates subjected to axial uniform pressure load and thermal load. The design objective is the maximization of the weighted sum of the critical buckling load and fundamental frequency. The design variable is the fibre orientations in the layers. The performance index is formulated as the weighted sum of individual objectives in order to obtain the optimum solutions of the design problem. The first-order shear deformation theory is used for the mathematical formulation. Finally, the effects of different weighting factors, annularity, sector angle and boundary conditions on the optimal design are investigated and the results are compared.
Optimal design of laminated composite plates to maximise fundamental frequency using MFD method
Topal, Umut,Uzman, Umit Techno-Press 2006 Structural Engineering and Mechanics, An Int'l Jou Vol.24 No.4
This paper deals with optimal fibre orientations of symmetrically laminated fibre reinforced composite structures for maximising the fundamental frequency of small-amplitude. A set of fiber orientation angles in the layers are considered as design variable. The Modified Feasible Direction method is used in order to obtain the optimal designs. The effects of number of layers, boundary conditions, laminate thicknesses, aspect ratios and in-plane loads on the optimal designs are studied.
Buckling load optimization of laminated plates via artificial bee colony algorithm
Umut Topal,Hasan Tahsin Öztürk 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.4
In this present work, Artificial Bee Colony Algorithm (ABCA) is used to optimize the stacking sequences of simply supported antisymmetric laminated composite plates with criticial buckling load as the objective functions. The fibre orientations of the layers are selected as the optimization design variables with the aim to find the optimal laminated plates. In order to perform the optimization based on the ABCA, a special code is written in MATLAB software environment. Several numerical examples are presented toillustrate this optimization algorithm for different plate aspect ratios, number of layers and load ratios.
Buckling load optimization of laminated plates via artificial bee colony algorithm
Topal, Umut,Ozturk, Hasan Tahsin Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.4
In this present work, Artificial Bee Colony Algorithm (ABCA) is used to optimize the stacking sequences of simply supported antisymmetric laminated composite plates with criticial buckling load as the objective functions. The fibre orientations of the layers are selected as the optimization design variables with the aim to find the optimal laminated plates. In order to perform the optimization based on the ABCA, a special code is written in MATLAB software environment. Several numerical examples are presented to illustrate this optimization algorithm for different plate aspect ratios, number of layers and load ratios.
Buckling load optimization of laminated plates resting on Pasternak foundation using TLBO
Topal, Umut,Vo-Duy, Trung,Dede, Tayfun,Nazarimofrad, Ebrahim Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.6
This paper deals with the maximization of the critical buckling load of simply supported antisymmetric angle-ply plates resting on Pasternak foundation subjected to compressive loads using teaching learning based optimization method (TLBO). The first order shear deformation theory is used to obtain governing equations of the laminated plate. In the present optimization problem, the objective function is to maximize the buckling load factor and the design variables are the fibre orientation angles in the layers. Computer programming is developed in the MATLAB environment to estimate optimum stacking sequences of laminated plates. A comparison also has been performed between the TLBO, genetic algorithm (GA) and differential evolution algorithm (DE). Some examples are solved to show the applicability and usefulness of the TLBO for maximizing the buckling load of the plate via finding optimum stacking sequences of the plate. Additionally, the influences of different number of layers, plate aspect ratios, foundation parameters and load ratios on the optimal solutions are investigated.
Shear buckling analysis of cross-ply laminated plates resting on Pasternak foundation
Topal, Umut,Nazarimofrad, Ebrahim,Kholerdi, Seyed Ebrahim Sadat Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.3
This paper presents the shear buckling analysis of symmetrically laminated cross-ply plates resting on Pasternak foundation under pure in-plane uniform shear load. The classical laminated plate theory is used for the shear buckling analysis of laminated plates. The Rayleigh-Ritz method with novel plate shape functions is proposed to solve the differential equations and a computer programming is developed to obtain the shear buckling loads. Finally, the effects of the plate aspect ratios, boundary conditions, rotational restraint stiffness, translational restraint stiffness, thickness ratios, modulus ratios and foundation parameters on the shear buckling of the laminated plates are investigated.
Umut Topal 국제구조공학회 2013 Steel and Composite Structures, An International J Vol.14 No.3
This paper deals with the applicability of a new extended layerwise optimization method for thermal buckling load optimization of laminated composite plates. The design objective is the maximization of the critical thermal buckling of the laminated plates. The fibre orientations in the layers are considered as design variables. The first order shear deformation theory (FSDT) is used for the finite element solution of the laminates. Finally, the numerical analysis is carried out to show the applicability of extended layerwise optimization algorithm of laminated plates for different parameters such as plate aspect ratios and boundary conditions.
Pareto optimum design of laminated composite truncated circular conical shells
Umut Topal 국제구조공학회 2013 Steel and Composite Structures, An International J Vol.14 No.4
This paper deals with multiobjective optimization of symmetrically laminated composite truncated circular conical shells subjected to external uniform pressure load and thermal load. The design objective is the maximization of the weighted sum of the critical buckling load and fundamental frequency. The design variable is the fibre 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 laminated truncated conical shells. Finally, the effect of different weighting factors, length-to-radius ratio, semi-cone angle and boundary conditions on the optimal design is investigated and the results are compared.
Frequency optimization for laminated composite plates using extended layerwise approach
Umut Topal 국제구조공학회 2012 Steel and Composite Structures, An International J Vol.12 No.6
This paper deals with the applicability of extended layerwise optimization method (ELOM) for frequency optimization of laminated composite plates. The design objective is the maximization of the fundamental frequency of the laminated plates. The fibre orientations in the layers are considered as design variables. The first order shear deformation theory (FSDT) is used for the finite element solution of the laminates. Finally, the numerical analysis is carried out to show the applicability of extended layerwise optimization algorithm of laminated plates for different parameters such as plate aspect ratios and boundary conditions.
Buckling load optimization of laminated composite stepped columns
Umut Topal 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.1
This paper deals with critical buckling load optimization of symmetric angle-ply laminated stepped flat columns under axial compression load. The design objective is the maximization of the critical buckling load and the design variable is the fiber orientations in the layers of the laminates. The classical laminate plate theory is used for the finite element solution of the laminated stepped flat columns. The modified feasible direction (MFD) method is used for the optimization routine. For this purpose, a program based on FORTRAN is exploited. Finally, the optimization results are presented for width ratios (b/B), ratios of fillet radius (r1/r2), aspect ratios (L/B) and boundary conditions. The results are presented in graphical and tabular forms and the results are compared.