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Öğe HİBRİD KONTROLLÜ TABAN İZOLASYONLU SİSTEMLERİN OPTİMİZASYONU(2020) Ulusoy, SerdarBu çalışmada, yüksek sönümlü kauçuk mesnet modeline aktif kontrol sistemi uygulanarak, hibrid kontrollü taban izolasyonlu sistemlerin darbe tipi titreşim içeren yakın fay etkisi altında davranışı incelenmiştir. Bu kapsamda, yapı tepkimelerindeki değişimin daha iyi irdelenmesi için hibrid kontrollü taban izolasyonlu yapı modelinin etkin titreşim periyodu sırasıyla 2.0, 3.0 ve 4.0 sn. ve her bir periyot için etkin sönüm oranı %20 ve %30 olarak alınmıştır. Taban izolasyonunun bulunduğu kata aktif tendonlar yerleştirilerek, deprem kaydının her adımı için tendonlara uygulanacak kontrol kuvveti ve oluşan yanal ötelemeler hesaplanmıştır. Orantı-İntegral-Türev (PID) kontrolcüsünün kontrol kuvvetine, yapının toplam kütlesine bağlı olarak sınır konulmuştur. Kontrolcünün parametreleri ise öğretim-öğrenme tabanlı algoritma (TLBO) ile belirlenmiştir. Sonuç olarak hibrid kontrollü taban izolasyonlu yapı modellerinde yanal ötelemelerin önemli ölçüde azaldığı tespit edilmiştir.Öğe HİBRİD KONTROLLÜ TABAN İZOLASYONLU SİSTEMLERİN OPTİMİZASYONU(Konya Technical University, 2020) Ulusoy, SerdarBu çalışmada, yüksek sönümlü kauçuk mesnet modeline aktif kontrol sistemi uygulanarak, hibrid kontrollü taban izolasyonlu sistemlerin darbe tipi titreşim içeren yakın fay etkisi altında davranışı incelenmiştir. Bu kapsamda, yapı tepkimelerindeki değişimin daha iyi irdelenmesi için hibrid kontrollü taban izolasyonlu yapı modelinin etkin titreşim periyodu sırasıyla 2.0, 3.0 ve 4.0 sn. ve her bir periyot için etkin sönüm oranı %20 ve %30 olarak alınmıştır. Taban izolasyonunun bulunduğu kata aktif tendonlar yerleştirilerek, deprem kaydının her adımı için tendonlara uygulanacak kontrol kuvveti ve oluşan yanal ötelemeler hesaplanmıştır. Orantı-İntegral-Türev (PID) kontrolcüsünün kontrol kuvvetine, yapının toplam kütlesine bağlı olarak sınır konulmuştur. Kontrolcünün parametreleri ise öğretim-öğrenme tabanlı algoritma (TLBO) ile belirlenmiştir. Sonuç olarak hibrid kontrollü taban izolasyonlu yapı modellerinde yanal ötelemelerin önemli ölçüde azaldığı tespit edilmiştir.Öğe Introduction and Review on Active Structural Control(Springer Science and Business Media Deutschland GmbH, 2022) Ulusoy, Serdar; Nigdeli, Sinan Melih; Bekdaş, GebrailThe number of stories of structures has been increased to meet the needs of people or long-span bridges are built for easier transportation. However, various destructive dynamic loads such as earthquakes and strong winds have negative effects on the structure without control systems. Therefore, control systems are necessary for these constructions. Furthermore, it is not enough for these constructions to be just safe and reliable. Constructions should be less exposed to vibrations under the influence of earthquakes and strong winds. For this reason, an external power source (activator) that can handle the large horizontal loads in these structures and a system that controls this source are needed. This study summarizes different active control systems, control techniques and studies on active structural control. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.Öğe Metaheuristic algorithms in optimum design of reinforced concrete beam by investigating strength of concrete(2020) Ulusoy, Serdar; Kayabekir, Aylin Ece; Bekdaş, Gebrail; Niğdeli, Sinan MelihThe locations of structural members can be provided according to architectural pro-jects in the design of reinforced concrete (RC) structures. the design of dimensions isthe subject of civil engineering, and these designs are done according to the expe-rience of the designer by considering the regulation suggestions, but these dimen-sions and the required reinforcement plan may not be optimum. For that reason, the dimensions and detailed reinforcement design of RC structures can be found by using optimization methods. To reach optimum results, metaheuristic algorithms can be used. In this study, several metaheuristic algorithms such as harmony search, bat al-gorithm and teaching learning-based optimization are used in the design of several RC beams for cost minimization. the optimum results are presented for different strength of concrete. the results show that using high strength material for high flex-ural moment capacity has lower cost than low stretch concrete since doubly rein-forced design is not an optimum choice. the results prove that a definite metaheuris-tic algorithm cannot be proposed for the best optimum design of an engineering problem. According to the investigation of compressive strength of concrete, it can be said that a low strength material are optimum for low flexural moment, while a high strength material may be the optimum one by the increase of the flexural mo-ment as expected.Öğe Novel metaheuristic-based tuning of PID controllers for seismic structures and verification of robustness(Elsevier Ltd, 2021) Ulusoy, Serdar; Niğdeli, Sinan Melih; Bekdaş, GebrailIn the present study, an active structural control using metaheuristic tuned Proportional-Integral-Derivative (PID) type controllers is presented. The aim of the study is to propose a feasible active control application considering time delay and a feasible control force. In the optimum control methodology, near-fault directivity pulse was considered for ground motion. Three different metaheuristic algorithms are separately employed in the optimum tuning of PID parameters such as proportional gain, integral time and derivative time. The employed algorithms are Flower Pollination Algorithm, Teaching Learning Based Optimization and Jaya algorithm. The maximum control force limit is considered as a design constraint. The methodology contains the time delay consideration and a process to avoid the stability problem on the trial results during the optimization process. The method is explained in three stages as The Pre-Optimization Stage, The Dynamic Analysis Stage and The Optimization Stage. The optimum PID parameters of different algorithms are very different, but the performance of active control is similar since a similar control signal can be generated by different proportion of controller gains such as proportion, integral and derivative processes. As the conclusion of the study, the amount of control force must be chosen carefully since big control forces may resulted with stability problems if the control system has long delay. © 2020Öğe Optimum active controlled SDOF structures under pulse-type ground motions via harmony search(Springer Science and Business Media Deutschland GmbH, 2021) Ulusoy, Serdar; Niğdeli, Sinan Melih; Bekdaş, GebrailIn this study, the active controlled single degree of freedom (SDOF) structures with 0.5, 1.0 and 2.0 s period are investigated under various pulse-type ground motions (1.5, 2.0, and 2.5 s) to optimally tune the parameters of proportional–integral–derivative (PID)-type controllers. The damping ratio value is assumed as 5%. The paper proposes a methodology to determine the proportional gain (Kp), integral gain (Ti), and derivative gain (Td) using Harmony Search algorithm (HS) which is one of the metaheuristic-based methods. The performance index of active controlled structures is the displacement feedback. Also, the control force limit as 50% of the total mass of the structure and the time delay effect 20 ms were considered in term of feasibility and stability of active controlled structures. According to the results, the optimum tuned PID controller parameters has major effects on the structural responses of SDOF structures. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Öğe Optimum Design of Reinforced Concrete Columns in Case of Fire(Springer Science and Business Media Deutschland GmbH, 2023) Günay, Uğur; Ulusoy, Serdar; Bekdaş, Gebrail; Nigdeli, Sinan MelihWhen designing load-bearing reinforced concrete components, external factors such as fire should be taken into account in addition to horizontal and vertical forces. Parameters such as cross-section of the reinforced concrete components, concrete cover, material properties and quantity of the concrete steel affect significantly the fire resistance of the reinforced concrete section exposed to fire. In this study, optimal cross-sections are obtained for 30, 60 and 90 fire duration taking into account the different cross-sections and concrete cover of the reinforced concrete column. The method for calculating the optimal sections of reinforced concrete columns is the modified metaheuristic algorithm, which is a combination of Flower Pollination Algorithm (FPA) with Jaya Algorithm (JA). The behavior of reinforced concrete column in case of fire is investigated according to EN-1992-1-2 (Eurocode 2: Design of reinforced concrete structures-Part 1–2: General rules—Structural fire design). The Eurocode offers 3 different methods for the fire design of concrete structures (simplified, advanced calculation methods and the tabulated date). In this study, optimal results are obtained in the tabulated date section. Thus, some limitations in EN-1992-1-2 such as minimum reinforcement cross-sectional area and column buckling length have been overcome. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.Öğe Optimum design of timber structures under fire using metaheuristic algorithm(Croatian Association of Civil Engineers, 2022) Ulusoy, SerdarOne of the major tasks of structural engineers is to reduce the building cost. Thus, an effective optimization of structural elements is gaining in importance every day. The teaching-learning-based optimization (TLBO), which is one of metaheuristic algorithms, for an optimum design and analysis of timber structures under fire in accordance with EN 1995 1-2 (Eurocode 5: Design of Timber structures -Part 1-2 General structural fire design), is proposed in this study. The objective function in this algorithm is the building cost of timber structures under fire, considering premature collapse of the structure and limitation of fire spread. A structure made of wood is investigated under different times of fire exposure in order to determine the cross-section and wood type of structural elements. In conclusion, the cross section and strength of structural elements made of wood can be effectively and rapidly optimized with TLBO according to EN 1995 1-2.Öğe Performance of optimum tuned PID controller with different feedback strategies on active-controlled structures(MDPI-Multidisciplinary Digital Publishing Institute, 2021) Ulusoy, Serdar; Bekdaş, Gebrail; Niğdeli, Sinan Melih; Kim, Sanghun; Geem, Zong WooIn this study, multi-story structures with different combinations (on each floor and only the first floor) of active tendon control systems driven by a proportional-integral-derivative (PID) controller were actively controlled. The PID parameters, K-p (proportional gain), T-d (derivative gain), and T-i (integral gain) for each structure, were optimally tuned by using both the harmony search algorithm (HS) and flower pollination algorithm (FPA), which are metaheuristic algorithms. In two different active-controlled structures, which are formed according to the position of the PID, the structural responses under near-fault records defined in FEMA P-695 are examined to determine the appropriate feedback which was applied for displacement, velocity, acceleration, and total acceleration. The performance of the different feedback strategies on these two active-controlled structures is evaluated. As a result, the acceleration feedback is suitable for all combinations of the active control system with a PID controller. The HS algorithm outperforms the optimum results found according to the FPA.Öğe Sizing optimization of the protected steel components at elevated temperature. revista de la construcción(Journal of Construction, 2023) Ulusoy, SerdarIn this paper, the metaheuristic algorithms such as Flower pollination and Harmony search algorithms are pro-posed to optimize the sizes of the steel components at the elevated temperature dealing with EN 1993 1-2. The purpose of these algorithms inspired by nature is to obtain the appropriate cross-section properties of the welded I sections. Numerical examples from the literature consisting of the protected steel structural components have been resized under different fire situations such as 30-, 60-and 90-minutesfire time. Based on the results from the numerical examples, the effect of the fire protection materials on the objective function (total weight of the steel structures) is quite high and the reduction ofthe total cost is almost 30% compared with the other studies. In addition, one of the most important duties of civil engineers, ensuring the balance between economic efficiency and safety, is fulfilled in a short time with the aid of the metaheuristic algorithms.Öğe The effect of SSI and impulsive motions on optimum active controlled MDOF structure(Springer Science and Business Media Deutschland GmbH, 2021) Ulusoy, Serdar; Niğdeli, Sinan Melih; Bekdaş, GebrailIn this study, active controlled ten-story structures including soil-structure interaction (SSI) are investigated under different type of ground motions (near-fault and far ground motions) defined in FEMA P-695 to show the effect of earthquake records on SSI. In structures, where active tendons are located on each floor, the proportional-integral-derivative (PID) controllers are used. Optimum tuning of PID control parameters are calculated with the teaching-learning-based algorithm (TLBO) and harmony search algorithms (HSA) which are commonly used metaheuristic algorithms. The properties such as swaying and rocking stiffness and damping of dense and soft soils were added to the foundation of the structures to consider the soil-structure interaction. The changes of structural reactions in two types of earthquake records are examined by decreasing or increasing these properties of soils by 10 and 20%. As a result, reduction and enhancement of properties of soft soil in structural responses are changed significantly, while these values are not changed much for dense soil. © 2021, Springer Nature Switzerland AG.
