Composed material models for nonlinear behavior of reinforced concrete

Tayfun Dede,Yusuf Ayvaz 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.12 No.3

The purpose of this study is to present different composed material models for reinforced concrete structures (RC). For this aim a nonlinear finite element analysis program is coded in MATLAB. This program contains several yield criteria and stress-strain relationships for compression and tension behavior of concrete. In this study, the well-known criteria, Drucker-Prager, von Mises, Mohr Coulomb, Tresca, and two new criteria, Hsieh-Ting-Chen and Bresler-Pister, are taken into account. It is concluded that the coded program, the new yield criteria, and the models considered can be effectively used in the nonlinear analysis of reinforced concrete beams.

Structural optimization with teaching-learning-based optimization algorithm

Tayfun Dede,Yusuf Ayvaz 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.4

In this paper, a new efficient optimization algorithm called Teaching–Learning-Based Optimization (TLBO) is used for the least weight design of trusses with continuous design variables. The TLBO algorithm is based on the effect of the influence of a teacher on the output of learners in a class. Several truss structures are analyzed to show the efficiency of the TLBO algorithm and the results are compared with those reported in the literature. It is concluded that the TLBO algorithm presented in this study can be effectively used in the weight minimization of truss structures.

Structural optimization with teaching-learning-based optimization algorithm

Dede, Tayfun,Ayvaz, Yusuf Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.4

In this paper, a new efficient optimization algorithm called Teaching-Learning-Based Optimization (TLBO) is used for the least weight design of trusses with continuous design variables. The TLBO algorithm is based on the effect of the influence of a teacher on the output of learners in a class. Several truss structures are analyzed to show the efficiency of the TLBO algorithm and the results are compared with those reported in the literature. It is concluded that the TLBO algorithm presented in this study can be effectively used in the weight minimization of truss structures.

A teaching learning based optimization for truss structures with frequency constraints

Dede, Tayfun,Togan, Vedat Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.4

Natural frequencies of the structural systems should be far away from the excitation frequency in order to avoid or reduce the destructive effects of dynamic loads on structures. To accomplish this goal, a structural optimization on size and shape has been performed considering frequency constraints. Such an optimization problem has highly nonlinear property. Thus, the quality of the solution is not independent of the optimization technique to be applied. This study presents the performance evaluation of the recently proposed meta-heuristic algorithm called Teaching Learning Based Optimization (TLBO) as an optimization engine in the weight optimization of the truss structures under frequency constraints. Some examples regarding the optimization of trusses on shape and size with frequency constraints are solved. Also, the results obtained are tabulated for comparison. The results demonstrated that the performance of the TLBO is satisfactory. Additionally, TLBO is better than other methods in some cases.

Continuous size optimization of large-scale dome structures with dynamic constraints

Tayfun DEDE,Maksym Grzywiński,Jacek Selejdak 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.4

In this study size optimization of large-scale dome structures with dynamic constraints is presented. In the optimal design of these structure, the Jaya algorithm is used to find minimal size of design variables. The design variables are the cross-sectional areas of the steel truss bar elements. To take into account the constraints which are the first five natural frequencies of the structures, the finite element analysis is coded in Matlab programs using eigen values of the stiffness matrix of the dome structures. The Jaya algorithm and the finite elements codes are combined by the help of the Matlab - GUI (Graphical User Interface) programming to carry out the optimization process for the dome structures. To show the efficiency and the advances of the Jaya algorithm, 1180 bar dome structure and the 1410 bar dome structure were tested by taking into the frequency constraints. The optimal results obtained by the proposed algorithm are compared with those given in the literature to demonstrate the performance of the Jaya algorithm. At the end of the study, it is concluded that the proposed algorithm can be effectively used in the optimal design of large-scale dome structures.

A teaching learning based optimization for truss structures with frequency constraints

Tayfun Dede,Vedat Toğan 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.4

Natural frequencies of the structural systems should be far away from the excitation frequency in order to avoid or reduce the destructive effects of dynamic loads on structures. To accomplish this goal, a structural optimization on size and shape has been performed considering frequency constraints. Such anoptimization problem has highly nonlinear property. Thus, the quality of the solution is not independent of the optimization technique to be applied. This study presents the performance evaluation of the recently proposed meta-heuristic algorithm called Teaching Learning Based Optimization (TLBO) as an optimization engine in the weight optimization of the truss structures under frequency constraints. Some examples regarding the optimization of trusses on shape and size with frequency constraints are solved. Also, the results obtained are tabulated for comparison. The results demonstrated that the performance of the TLBO is satisfactory. Additionally, TLBO is better than other methods in some cases.

Jaya algorithm to solve single objective size optimization problem for steel grillage structures

Tayfun Dede 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.2

The purpose of this paper is to present a new and efficient optimization algorithm called Jaya for optimum design of steel grillage structure. Constrained size optimization of this type of structure based on the LRFD-AISC is carried out with integer design variables by using cross-sectional area of W-shapes. The objective function of the problem is to find minimum weight of the grillage structure. The maximum stress ratio and the maximum displacement in the inner point of steel grillage structure are taken as the constraint for this optimization problem. To calculate the moment and shear force of the each member and calculate the joint displacement, the finite elements analysis is used. The developed computer program for the analysis and design of grillage structure and the optimization algorithm for Jaya are coded in MATLAB. The results obtained from this study are compared with the previous works for grillage structure. The results show that the Jaya algorithm presented in this study can be effectively used in the optimal design of grillage structures.

Application of Teaching-Learning-based-Optimization Algorithm for the Discrete Optimization of Truss Structures

Tayfun Dede 대한토목학회 2014 KSCE JOURNAL OF CIVIL ENGINEERING Vol.18 No.6

The aim of this study is to present a new efficient optimization algorithm called Teaching-Learning-Based Optimization (TLBO). The TLBO algorithm is based on the effect of the influence of a teacher on the output of learners in a class. Several benchmarkproblem related truss structures with discrete design variables are used to show the efficiency of the TLBO algorithm and the resultsare compared with those reported in the literature. It is concluded that the TLBO algorithm presented in this study can be effectivelyused in the weight minimization of truss structures.

Stacking Sequence Optimization for Maximum Fundamental Frequency of Simply Supported Antisymmetric Laminated Composite Plates using Teaching–Learning-Based Optimization

Umut Topal,Tayfun Dede,Hasan Tahsin Öztürk 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.6

This paper proposed a technique based on Teaching–learning-based Optimization (TLBO) for fundamental frequency optimization of simply supported antisymmetric laminated composite plates. The fibre orientations of the layers are selected as the optimization design variables with the aim to find the optimal laminated plates. The first order shear deformation theory is used to calculate the natural frequencies of laminates. In order to perform the optimization based on the TLBO, a special code is written in MATLAB software environment. Several numerical examples are presented to show the efficiency of the proposed algorithm. Also, the optimization problems are solved using other optimization algorithm such as Artifical Bee Colony (ABC) algorithm and the results are compared. It is concluded that TLBO algorithm can effectively be used for fundamental frequency optimization of antisymmetric laminated plates. The CPU time and the number of function evaluations required by TLBO are much smaller than those of the other algorithms tested. This indicates that TLBO is a competitive optimization algorithm for this class of problems.

Optimization of cables size and prestressing force for a single pylon cable-stayed bridge with Jaya algorithm

Barbaros ATMACA,Tayfun DEDE,Maksym GRZYWİNSKİ 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.6

In recent years, due to the many advantages cable-stayed bridges have often constructed in medium and long span. These advantages can be listed as an aesthetically pleasing appearance, economic and easy construction, etc. The main structural elements of cable-stayed bridges are listed as deck, pylon, cables and foundation. Perhaps one of the most vital and expensive of these structural elements is stay-cables. Stay-cables ensure the allowable displacement and distribution of bending moments along the bridge deck with prestressing force. Therefore the optimum design of the stay-cables and prestressing force are very important in achieving the performance expected from the cable-stayed bridges. This paper aims to obtain the stay-cables size and prestressing force optimization of the cable-stayed bridge. For this purpose, single pylon and fan type cable configuration Manavgat Cable-Stayed Bridge was selected as an example. The three dimensional (3D) finite element model (FEM) of the bridge was created with SAP2000. Analysis of the 3D FEM of the bridge was conducted under the different combined effects of the self-weight of the structural element, prestressing force of stay-cable and live load. Stay-cable stress and deck displacement were taken into account as constraints for the optimization problem. To optimize this existing bridge a metaheuristic algorithm named Jaya was used in the optimization process. 3D FEM of the selected bridge was repeatedly analyzed by using Open Applicable Programming Interface (OAPI) properties of SAP2000. To carry out the optimization process the developed program which integrates the Jaya algorithm and the required codes for calling SAP2000 is coded in MATLAB. At the end of the study, the total weight of the stay-cables was reduced more than 40% according to existing stay cables under loads taken into account.