Yazar "Karabörk, Turan" seçeneğine göre listele

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    A comparison of the effect of SSI on base isolation systems and fixed-base structures for soft soil
    (Techno Press, 2014) Karabörk, Turan; Deneme, İbrahim Özgür; Bilgehan, R. Pelin
    This study investigated the effect of soil-structure interaction (SSI) on the response of base-isolated buildings. Seismic isolation can significantly reduce the induced seismic loads on a relatively stiff building by introducing flexibility at its base and avoiding resonance with the predominant frequencies of common earthquakes. To provide a better understanding of the movement behavior of multi-story structures during earthquakes, this study analyzed the dynamic behavior of multi-story structures with high damping rubber bearing (HDRB) behavior base isolation systems that were built on soft soil. Various models were developed, both with and without consideration of SSI. Both the superstructure and soil were modeled linearly, but HDRB was modeled non-linearly. The behavior of the specified models under dynamic loads was analyzed using SAP2000 computer software. Erzincan, Marmara and Duzce Earthquakes were chosen as the ground motions. Following the analysis, the displacements, base shear forces, top story accelerations, base level accelerations, periods and maximum internal forces were compared in isolated and fixed-base structures with and without SSI. The results indicate that soil-structure interaction is an important factor (in terms of earthquakes) to consider in the selection of an appropriate isolator for base-isolated structures on soft soils.
  • Küçük Resim
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    Çelik yapılarda kullanılan diyagonal çelik çaprazların yapay arı koloni algoritması ile optimizasyonu
    (Uludağ Üniversitesi, 2018) Karabörk, Turan; Sönmez, Mustafa; Aydın, Ersin; Çelik, Tülin; Bölükbaş, Yakup
    Diyagonal çelik çapraz (DÇÇ) sistemler, mevcut yapının deprem performansının iyileştirilmesinde veya yeni yapının depreme dayanıklı olarak tasarlanmasında yaygın olarak kullanılan yöntemlerden birisidir. Bu sistemler yapının yatay yük taşıma kapasitesini arttırır ve yapının yanal rijitliğine katkı sağlamaktır. Çelik diyagonal çaprazların yapı sistemindeki yerleşimi, yapı sistemin performansını etkileyen önemli etkenlerden birisidir. Bu çalışma, çelik çaprazların yerleşimdeki optimum dağılımın belirlenmesi için yapay arı koloni optimizasyon tekniği kullanılarak yeni bir algoritma sunulmuştur. Tepe deplasmanına ve taban kesme kuvvetine bağlı transfer fonksiyonları amaç fonksiyonu olarak seçilmiştir. Buradaki temel amaç, belirlenen kısıtlar altında amaç fonksiyonlarının minimize edilmesidir. Tasarım değişkeni olarak her kata yerleştirilen çelik çaprazların rijitlikleri seçilmiştir. Ayrıca, çelik çaprazların toplam rijitliği, optimizasyon probleminin aktif kısıtlı olarak belirlenmiştir. Hazırlanan optimizasyon algoritmasının performansının test edilmesi amacıyla 20 katlı çelik yapı modeli oluşturulmuş ve El Centro depremi kaydı kullanılarak zaman tanım alanında dinamik analiz yapılmıştır. Yapay arı koloni algoritması kullanılarak elde edilen optimum çelik çapraz yerleşimi, düzgün dağılım ile karşılaştırılmıştır. Bu bulgular göstermiştir ki, tasarlanan algoritma ile belirlenen optimum diyagonal çelik çapraz dağılımı, her bir amaç fonksiyonu için tatmin edici sonuçlar vermiştir.
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    New metal connectors developed to improve the shear strength of stone masonry walls
    (Techno-Press, 2014) Karabörk, Turan; Koçak, Yılmaz
    Stone masonry structures are widely used around the world, but they deteriorate easily, due to low shear strength capacity. Many techniques have been developed to increase the shear strength of stone masonry constructions. The aim of this experimental study was to investigate the performance of stone masonry walls strengthened by metal connectors as an alternative shear reinforcement technique. For this purpose, three new metal connector (clamp) types were developed. The shear strength of the walls was improved by applying these clamps to stone masonry walls. Ten stone masonry walls were structurally tested in diagonal compression. Various parameters regarding the in-plane behavior of strengthening stone masonry walls, including shear strength, failure modes, maximum drift, ductility, and shear modulus, were investigated. Experimentally obtained shear strengths were confirmed by empirical equations. The results of the study suggest that the new clamps developed for the study effectively increased the levels of shear strength and ductility of masonry constructions.
  • Küçük Resim
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    Optimization damping of viscous dampers to prevent collisions between adjacent structures with unequal heights as a case study
    (Springer, 2020) Karabörk, Turan
    Currently, construction is very dense especially in city centers, and adjacent structures are generally preferred in areas where available land is scarce. These structures often have different heights and are generally constructed without a structural connection to each other. Since adjacent structures may have different dynamic characteristics, collisions may occur when the structures contact each other under earthquake effects. Therefore, this study investigated the optimum values of viscous dampers placed between adjacent structures of unequal height to prevent collisions under different earthquake effects. In the optimization problem determined, the objective function was selected to minimize the total damping coefficient of viscous dampers added to the stories. A new algorithm utilizing numerical optimization methods to find the values of dampers between the structures was introduced to avoid collisions between adjacent structures of different heights. Structural models were used to examine the effects of variations in the height ratios of the structures, the value of damping from the viscous dampers on each floor, the vibration mode of the structures and the values of relative displacement. The proposed method showed that when viscous dampers were optimally placed between adjacent buildings of different heights, the relative displacements under earthquake impacts could be reduced below a target value, thereby avoiding the risk of collisions.
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    Optimum design of viscous dampers to prevent pounding of adjacent structures
    (TECHNO-PRESS, 2019) Karabörk, Turan; Aydın, Ersin
    This study investigates a new optimal placement method for viscous dampers between structures in order to prevent pounding of adjacent structures with different dynamic characteristics under earthquake effects. A relative displacement spectrum is developed in two single degree of freedom system to reveal the critical period ratios for the most risky scenario of collision using El Centro earthquake record (NS). Three different types of viscous damper design, which are classical, stair and X-diagonal model, are considered to prevent pounding on two adjacent building models. The objective function is minimized under the upper and lower limits of the damping coefficient of the damper and a target modal damping ratio. A new algorithm including time history analyses and numerical optimization methods is proposed to find the optimal dampers placement. The proposed design method is tested on two 12-storey adjacent building models. The effects of the type of damper placement on structural models, the critical period ratios of adjacent structures, the permissible relative displacement limit, the mode behavior and the upper limit of damper are investigated in detail. The results of the analyzes show that the proposed method can be used as an effective means of finding the optimum amount and location of the dampers and eliminating the risk of pounding.
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    Performance of multi-storey structures with high damping rubber bearing base isolation systems
    (Techno Press, 2011) Karabörk, Turan
    Base isolation, having quite simple contents, aims to protect the buildings from earthquakeinduced damages by installing structural components having low horizontal stiffness between substructure and superstructure. In this study, an appropriate base isolation system for 2-D reinforced concrete frame is investigated. For different structural heights, the structural systems of 2, 3 and 4 bays are modeled by applying base isolation systems and results are compared with conventional structural systems. 1999 Marmara earthquake data is used for applying the model by time history method in SAP2000 package. Results of various parameters such as base shear force, structure drift ratio, structure period and superstructure acceleration are discussed for all models.
  • Küçük Resim
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    Using an artificial bee colony algorithm for the optimal placement of viscous dampers in planar building frames
    (Springer, 2013) Sönmez, Mustafa; Aydın, Ersin; Karabörk, Turan
    In this study, an Artificial Bee Colony Algorithm (ABCA) is used to obtain the optimal size and location of viscous dampers in planar buildings to reduce the damage to the frame systems during an earthquake. The transfer function amplitude of the top displacement and the elastic base shear force evaluated at the first natural circular frequency of structures are chosen as objective functions. The damper coefficients of the added viscous dampers are taken into consideration as design variables in a planar building frame. Transfer function amplitude of the top displacement and the amplitude of the elastic base shear force at the fundamental natural frequency are minimized under an active constraint on sum of the damper coefficients of the added dampers. According to two specified objective functions, an optimization algorithm based on the ABCA is proposed. The proposed method is verified by a gradient-based algorithm; steepest direction search algorithm (SDSA). The proposed ABCA and the SDSA are applied to find the optimal damper distribution for a nine-storey planar building then the optimal damper allocation obtained from the ABCA is investigated to rehabilitate models of irregular planar buildings. The validity of the proposed method was demonstrated through a time history analysis of the optimal damper designs, which were determined based on the frequency domain using the ABCA. The numerical results of the proposed optimal damper design method show that the use of the ABCA can be a practical and powerful tool to determine the optimal damper allocation in planar building structures.