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Öğe Adaptive Harmony Search for Cost Optimization of Reinforced Concrete Columns(Springer Science and Business Media Deutschland GmbH, 2022) Kayabekir, Aylin Ece; Nigdeli, Sinan Melih; Bekdaş, GebrailThe performance of metaheuristic algorithms used in engineering optimization is evaluated via the robustness of the method. To make a better algorithm for specific problems, investigations have to be continued by applying methods to new problems. In the present study, adaptive harmony search (AHS) that automatically updates the algorithm parameters is presented for optimum cost design of reinforced concrete (RC) columns. The results were compared with the approach that constant parameters within the optimization process. Results proved that AHS is not greatly affected by the choice of initial algorithm parameters. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.Öğe Analysis of Non-linear Structural Systems via Hybrid Algorithms(Springer Science and Business Media Deutschland GmbH, 2022) Nigdeli, Sinan Melih; Bekdaş, Gebrail; Yücel, Melda; Kayabekir, Aylin Ece; Toklu, Yusuf CengizMetaheuristic methods are commonly used in the problems which are treating optimization of structural systems as to the topology, shape and size. It is currently shown that metaheuristic methods can also be used in the analysis of structural system by an application of the well-known mechanical principle of minimum energy. This method is called total potential optimization using metaheuristic methods (TPO/MA), and it is shown that this method has certain advantages in dealing with nonlinear problems and with the problems where classical methods including the Finite Element Method has some difficulties. In this paper, a retaining wall example that is generated via plane-strain members is presented and hybrid algorithms using the Jaya algorithm are investigated. The hybrid algorithms may have advantages on the needed iteration number to reach the final value. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.Öğe Cantilever Soldier Pile Design: The Multiobjective Optimization of Cost and CO2 Emission via Pareto Front Analysis(MDPI, ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND, 2022) Bekdaş, Gebrail; Akbay Arama, Zülal; Türkakın, Osman Hürol; Kayabekir, Aylin Ece; Geem, Zong WooIn the context of this study, it is focused on the design of cantilever soldier piles under the concept of Pareto optimality with multiobjective analyses of cost and CO2 emission considering the change in the excavation depth, the shear strength parameters of the foundation soil strata, and the unit costs and unit emission amounts of structural materials. Considering this aim, the harmony search algorithm was used as a tool to achieve the integrated effects of the solution variants. The lateral response of the soil mass was determined based on the active Rankine earth pressure theory and the design process was shaped according to the beams on the elastic foundation soil assumption. Moreover, the specification envisaged by the American Concrete Institute (ACI 318-11) was used to control the structural requirements of the design. Pareto front graphs and also design charts were created to achieve the eco- and cost optimization, simultaneously, for the design with arbitrarily selected cases to compare the results of the multiobjective analysis to minimize both the cost and the CO2 emission.Öğe The Development of Hybrid Metaheuristics in Structural Engineering(Springer Science and Business Media Deutschland GmbH, 2023) Kayabekir, Aylin Ece; Nigdeli, Sinan Melih; Bekdaş, GebrailIn engineering designs, the variables in the problems are needed to define by checking several constraints. In that case, the problem is a nonlinear one that needs several iterations when the best suitable solution is wanted. To find the best solution, several algorithms may be employed to iteratively search for the optimum solution. These algorithms are inspired by happening or processes to provide different formulations. As the current trend, multiple algorithms are combined to update efficient features instead of using a metaphor. In this chapter, a review is presented for hybrid metaheuristics in structural engineering applications. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.Öğe Estimating Construction Material Indices with ARIMA and Optimized NARNETs(TECH SCIENCE PRESS, 871 CORONADO CENTER DR, SUTE 200, HENDERSON, NV 89052, 2023) Işıkdağ, Ümit; Hepsağ, Aycan; İmre Bıyıklı, Süreyya; Öz, Derya; Bekdaş, Gebrail; Geem, Zong WooConstruction Industry operates relying on various key economic indicators. One of these indicators is material prices. On the other hand, cost is a key concern in all operations of the construction industry. In the uncertain conditions, reliable cost forecasts become an important source of information. Material cost is one of the key components of the overall cost of construction. In addition, cost overrun is a common problem in the construction industry, where nine out of ten construction projects face cost overrun. In order to carry out a successful cost management strategy and prevent cost overruns, it is very important to find reliable methods for the estimation of construction material prices. Material prices have a time dependent nature. In order to increase the foreseeability of the costs of construction materials, this study focuses on estimation of construction material indices through time series analysis. Two different types of analysis are implemented for estimation of the future values of construction material indices. The first method implemented was Autoregressive Integrated Moving Average (ARIMA), which is known to be successful in estimation of time series having a linear nature. The second method implemented was Non-Linear Autoregressive Neural Network (NARNET) which is known to be successful in modeling and estimating of series with non-linear components. The results have shown that depending on the nature of the series, both these methods can successfully and accurately estimate the future values of the indices. In addition, we found out that Optimal NARNET architectures which provide better accuracy in estimation of the series can be identified/discovered as result of grid search on NARNET hyperparameters.Öğe A hybrid metaheuristic method for optimization of active tuned mass dampers(WILEY, 111 RIVER ST, HOBOKEN 07030-5774, NJ, 2022) Kayabekir, Aylin Ece; Niğdeli, Sinan Melih; Bekdaş, GebrailA metaheuristic-based tuning methodology for the optimization of active tuned mass dampers (ATMDs) is presented. The methodology considers both physical parameters of ATMDs and controller parameters of the control algorithm. The employed control algorithm is a proportional–integral–derivative type controller. ATMDs are used in structures in the reduction of structural responses resulted from earthquakes. The proposed methodologies must be feasible for real practices in construction, so consider all physical factors such as stroke capacity, limitation of the active control force, the time delay of the generated control signal, and a time-saving one. A novel hybrid metaheuristic algorithm that combines the specific advantages of four metaheuristics (harmony search, flower pollination algorithm, teaching-learning-based optimization and Jaya algorithm) is proposed for the optimization process. The results of the process showed that ATMDs are more effective for high values strike limitations, compared to TMDs. The feasibility and effectiveness of the optimum control method are also demonstrated on a full-size 76-story structure.Öğe Introduction and Overview: Structural Control and Tuned Mass Dampers(Springer Science and Business Media Deutschland GmbH, 2022) Bekdaş, Gebrail; Nigdeli, Sinan Melih; Kayabekir, Aylin EceIn this chapter, an introduction is presented for system dynamics and control. The main aim in the control of structures is to reduce vibrations and the vibration is defined then, the main concern of system dynamics and control such as control, automatic control, system, transfer function and control system types are given. Then, a short brief for structural control types such as active, passive, semi-active and hybrid are defined. Lastly, the content of the book “Optimization of Tuned Mass Dampers-Using Active and Passive Control” is presented. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.Öğe A Modified Jaya Algorithm for Optimum Design of Carbon Fiber-Reinforced Polymers(Springer Science and Business Media Deutschland GmbH, 2024) Nigdeli, Sinan Melih; Bekdaş, Gebrail; Kayabekir, Aylin EceIn this study, a modified Jaya algorithm is presented for a structural engineering problem. Jaya algorithm (JA) is a single-phase metaheuristic algorithm using best and worst existing solutions. The effects of these solutions are equally considered in the classical form. In the proposed modified algorithm, a weight factor is considered for these factors. This factor is randomly chosen to keep the algorithm as a parameter-free one. The results of modified JA (MJA) and JA are compared and evaluated for optimization of carbon fiber-polymers (CFRP) used for increasing the shear force capacity of reinforced concrete beams. The results show that MJA outperforms JA. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.Öğe Optimum Design and Tuning Applications in Structural Engineering via Swarm Intelligence(Springer Science and Business Media Deutschland GmbH, 2023) Bekdaş, Gebrail; Nigdeli, Sinan Melih; Kayabekir, Aylin EceAs all engineering disciplines, structural engineering problems are needed to be optimized and due to the nonlinear behavior of these problems, it is not possible to solve them mathematically, but metaheuristic methods are very successful in iterative optimization by assuming values for the design variables within a desired range of the user. In structural engineering problems, metaheuristic methods including swarm-intelligence-based algorithms are used in two groups of problems. Design optimization is the first group and the design like dimension, amount of material and orientations are optimally found for minimizing objectives related to cost, weight, CO2 emission and others. In these problems, constraints are found via design codes like steel and reinforced concrete structure design regulations. This group belongs to a design of a structure. The second group includes optimum tuning and it generally covers structural control applications. This group involves the optimum tuning of the additional control system of the structure that can be added to the newly constructed structure for better performance or existing ones to correct the failure or increase the existing performance. The role of engineers is to make the best possible structural design and optimization is important. More especially, tuning optimization is a must to provide acceptable performance. In this chapter, a review of existing studies about the design optimization of structural systems is presented for swarm intelligence-based algorithms. Then, optimum tuning applications are mentioned including the most important studies about tuned mass dampers. Finally, optimization problems are presented for design and tuning optimization. The RC retaining wall optimization was presented for two cases with and without toe projection and the optimization of a toe is 5% effective on reduction of cost. In span length optimization of frame structures, frame models with different stories have similar optimum span lengths. Active tuned mass dampers are up to 22.08% more effective than passive tuned mass dampers. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.Öğe Optimum Tuning of Active Mass Dampers via Metaheuristics(Springer Science and Business Media Deutschland GmbH, 2022) Kayabekir, Aylin Ece; Bekdaş, Gebrail; Nigdeli, Sinan MelihIn the present study, a metaheuristic-based optimization methodology that optimizes both physical parameters of active tuned mass dampers (ATMDs) and the tuning parameters of proportional-integral-derivative (PID) type used in the generation of the control force. As known, ATMDs are positioned on seismic structures to reduce structural responses. As the current target of today’s needs, the methodologies must be suitable for real structures. Due to that, the proposed method considers all limitations in practice like stroke capacity, control force limitation and time delay of the control signal. In addition to that, the process is a time-saving one with automated decision-making for non-effective candidate solutions during dynamic analysis. This method was tested by employing three different algorithms. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
