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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 Control of Reinforced Concrete Frame Structures via Active Tuned Mass Dampers(Springer-Verlag Singapore Pte Ltd, 2022) Kayabekir, Aylin Ece; Bekdas, Gebrail; Nigdeli, Sinan MelihIn this paper, an active structural control method called active tuned mass dampers (ATMDs) was applied to reinforced concrete frame structures. ATMD is positioned on the top of the structure and uses a proportional integral derivative (PID) controller. Both damper and PID controller properties are optimized via an improved harmony search algorithm. During the optimization, the limit of control force, stroke capacity of ATMD and time-delay of the control system is considered. As the numerical example, a 15-story frame building is presented and the optimum ATMD is effective to reduce maximum displacement by 37.5% for critical excitation.Öğe COST AND ENVIRONMENTAL FRIENDLY MULTI-OBJECTIVE OPTIMUM DESIGN OF REINFORCED CONCRETE COLUMNS(Scibulcom Ltd, 2022) Kayabekir, Aylin Ece; Bekdas, Gebrail; Nigdeli, Sinan Melih; Apak, SudiIn the construction industry, the aim is to construct low-profit structures that meet the demand of residents and safety measures, and also sustainability and environment-friendly measures need to be ensured in the production. Due to defined regulations in design codes to ensure stress capacity, ductility, and constructive needs, the optimum design problems are highly constrained which makes it a nonlinear one in defining the optimum design variables. In the present study, an optimisation methodology is presented via the use of a metaheuristic method called Harmony Search (HS) for reinforced concrete (RC) column members that having minimised cost and CO2 emission. The investigation is done for single objective cases of cost and CO2 emission together with multi-objective optimisation. According to the results, CO2 emission optimisation highly increases the cost of the design, while multi-objective cases lead to more low-profit results in the reduction of CO2 emission.Öğe Design Optimization of a Hybrid Vibration Control System for Buildings(Mdpi, 2023) Salaas, Basel; Bekdas, Gebrail; Ibrahim, Yasser E.; Nigdeli, Sinan Melih; Ezzat, Mohamed; Nawar, Mahmoud; Kayabekir, Aylin EceControl of high-rise structures under seismic excitations was investigated using a passive hybrid control system consisting of a base-isolation (BI) subsystem and a passive tuned liquid column damper (TLCD) system. Both of the systems were optimized considering using the other system in the same structure. An optimization method was developed, and a computer code was written based on dynamic analysis of the structure and metaheuristic optimization methods. Within the scope of the study, a general solution was found by using many earthquake records during the optimization process. Moreover, one of the most suitable and successful metaheuristic algorithms was used in this study. In addition, numerical simulations were performed on a benchmark high-rise building structure to investigate the effectiveness of the optimized hybrid control system in controlling the seismic response of the building. The performance of the base-isolated TLCD-controlled structure was examined when the TLCD was placed on the base floor by using a set of 44 recorded ground motions as base excitations. Based on the results obtained from this study, the use of a base-isolation subsystem decoupling the superstructure from the ground motions by lowering the structure's fundamental natural frequency reduces the structural responses of the building in most cases. The responses of the base-isolation subsystem were not too large since the parameters of the BI subsystem were optimized specifically for the investigated structure. Nevertheless, displacements of BI might exceed the maximum limit to undesirable values in some cases. The TLCD system appears to be quite effective in protecting the base-isolation subsystem by reducing its displacements to the maximum allowable limit or below when attached to it. Moreover, the proposed passive hybrid control system can effectively reduce the structural responses under seismic excitations.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 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.
