Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis An Investigation of Design Parameters Influencing Post-Fire Irreparable Structural Damage Limit(01. Izmir Institute of Technology, 2024) Demir, Uğur; Çelik, Elif Naz; Demir, UğurSon yıllarda, yangın durumunda oluşan deformasyonların sınırlandırılması, sonraki dönemde oluşabilecek onarılamaz hasarları önlemek amacıyla inşaat sektörü için zorunlu bir hale gelmiştir. Bu amaç doğrultusunda, bu çalışma, yangın etkisi altında betonarme yapısal sistemlerin kullanılabilirlik durumunu etkileyen kritik faktörleri detaylı bir şekilde incelemektedir. Araştırma, betonarme kirişlerin sehimlerinin, yangına maruz kalan kolonların yük taşıma kapasiteleri ve birleşik termal ve mekanik yükleme altındaki kolon öteleme oranlarının doğrusal olmayan sonlu eleman modellemeleri temelinde gerçekleştirilmiştir. Yapısal sistemler ve malzemelerin kullanılabilirlik sınırları önemli ölçüde göz önünde bulundurulmuştur. Yangın olayını simüle etmek için, kompartman alanı, havalandırma açıklıkları ve termal atalet gibi değişken özelliklere sahip parametrik bir yangın eğrisi kullanılmıştır. Hesaplama sürecini daha uygun hale getirmek amacıyla parametrik eğriler üretebilen bir yazılım çalışmaya dahil edilmiştir. Mekanik davranış, betonarme (RC) kirişin maksimum taşıma kapasitesi altında incelenmiştir. Mevcut yönetmeliklerde belirtilen kullanılabilirlik sınır durumu için verilen sehim sınırları ve öteleme oranları, sayısal bulgularla karşılaştırılmış; havalandırma koşullarının sehim davranışı üzerindeki etkisi buna bağlı olarak tartışılmıştır. Çalışma, yangından zarar görmüş RC elemanları ile belirli bir yangın senaryosu arasında bir ilişki kurulmasının mümkün olabileceğini ve bunun, tasarımda performans tabanlı yapısal yangın güvenliğinin ilerlemesine katkıda bulunabileceğini ortaya koymaktadır. Simülasyonların, yapısal yangın güvenliğinin sağlanmasında önemli bir bileşen olan mimarlara, binaların ilk tasarım aşamasında açıklıkların sayısını ve boyutlarını optimize etme, malzeme seçimi yapma ve kapalı alanların boyutlandırılması konusunda rehberlik etme potansiyeli bulunmaktadır.Master Thesis Structural Design of Rc Structures From Sustainable Development Perspective(01. Izmir Institute of Technology, 2023) Gültepe, Ekin; Dönmez, CemalettinThe growth of the population and changing demands have become a significant problem due to the limited resources of the earth. Climate change has increased the occurrence of natural events and probable disasters due to insufficient infrastructure. The economic, environmental, and social aspects of the problem necessitate sustainable practices. On the other hand, probable disaster dictates design decisions to keep the physical environment intact and resilient. Hence, the expectations from the construction industry are high. The industry also needs to tackle the task of lowering the existing high consumption levels of natural resources and energy. Being resilient under seismic events is paramount for the areas that have high seismicity. The general trend of using less material for sustainability purposes conflicts with the resilient seismic design decisions which typically cause an increase in the initial consumptions. The studies on resilience and sustainability hint that there might be design opportunities that serve both purposes together. In this study, such an opportunity for RC residential buildings is focused. The resilience and energy cost of a conventional moment-resisting frame and the same frame with increased robustness through the addition of shear walls are studied. It is presumed in addition to the increased robustness, the thermal impact of the additional concrete mass will create an advantage for energy consumption in the life cycle of the building. The design decision for shear walls is based on the proposal by Hassan and Sozen (1997). Nonlinear time history analysis is performed for both frames according to Turkish Earthquake Regulation. Results show that the robust frame has the needed resilience. The energy analysis shows that the frame with shear walls has significantly higher consumption initially. However, when the thermal impact of the concrete is included in the full life cycle, the energy consumption difference reduces from 18% to 4%. As a result, it could be stated that providing sufficient robustness to the structure by shear walls at targeted locations provides an opportunity to have a resilient and sustainable structure with a minor increase in total energy cost throughout the life cycle of the structure.Master Thesis Earthquake Response of R/C Frames With Reinforced Infill Walls(Izmir Institute of Technology, 2008) Yıldırım, Umut; Turan, GürsoyMost of the reinforced concrete structures that are built in the past few decades are in lack of ductility and lateral stiffness. In the content of the present work, a fast and economical remedy was searched to rehabilitate these type of buildings that are under high risk of earthquake damage.The strengthening technique needs to be finished in a short time without the people that live inside the buildings to move out. Furthermore, the chosen strengthening technique needs to be economical enough so that the home owner would not hesitate in making a decision of the rehabilitation.In regard of the above mentioned two criteria, existing infill clay brick walls may be strengthened by the addition of a wire mesh on the surface together with a layer of plaster. In order to investigate its effectiveness, a numerical investigation is carried out to study the behaviour of a strengthened infilled reinforced concrete (RC) frame using wire mesh under lateral reversed cyclic loading. A single span, one-story clay brick infilled RC frame is modeled and a nonlinear analysis is made.The analysis results indicate that the technique of strengthening with wire meshincreased the peak lateral load, ductility and energy dissipation.Master Thesis The Interaction of Reinforced Concrete Skeleton Systems Andarchitectural Form Subjected To Earthquake Effects(Izmir Institute of Technology, 2010) İnan, Tuğba; Korkmaz, Koray3 The interaction of architectural form and structural configuration has become a serious issue in the building industry because of the poor seismic performance of reinforced concrete buildings in Turkey. Therefore, it has a determinative role on earthquake behaviour of buildings. The study focuses on R/C skeleton systems which are commonly constructed in building industry of Turkey. In this study, structural irregularities in plan and vertical direction have been investigated in detail based on Turkish Earthquake Code, 2007. Four main cases are generated based on each structural irregularity in plan. These cases consist of 29 main parametric models and totally 265 models with sub models. They are designed as to have symmetrical or asymmetrical plan geometry and regular or irregular rigidity distribution. All models are analyzed by using the structural analyzing software, IdeCAD Static 6.0055. The changes in the earthquake behaviour of buildings were examined according to the number of stories, number of axes, configuration of structural elements, floor openings, projections in plan and vertical direction. Many findings are obtained and assessed as a result of the analysis for each structural irregularity. The most remarkable result shows that structural irregularities can be observed in completely symmetric buildings in terms of plan geometry and rigidity distribution due to the inaccurate structural system selection. Moreover, it has emerged that symmetry in the rigidity distribution is more important than the symmetry in the plan geometry.Master Thesis Behavior of Reinforced Concrete Slabs Subjeted To Impact Loads(Izmir Institute of Technology, 2013) Batarlar, Baturay; Saatcı, SelçukThis study presents the findings of an experimental program designed for investigating the behavior of RC slabs under low-velocity impact loads. Six RC slabs with dimensions 2015x2015x150 mm were tested at the Structural Laboratory of the Izmir Institute of Technology. To facilitate a comparison between the static and impact behavior of identical specimens, the slabs were cast in three identical pairs, such that one of the specimens was tested under impact loads whereas its identical twin was tested under static loads. To test the slabs under simply supported conditions, an innovative impact test setup was designed and manufactured, supporting the specimens at 20 locations along the perimeter and holding the specimens in place during the impact induced rebound. This setup was also used for the testing of the specimens under monotonically increasing static loads at the midpoint. Impact loads were induced on the specimens by a free falling drop-weight, impacting the specimens at the midpoint. The specimens were intensely instrumented with 20 load cells at each support location, 24 displacement transducers, 6 accelerometers and 12 strain gauges fixed to the reinforcing bars. Dynamic data was captured with the help of a high speed data acquisition system, capturing and recording the data at a rate of 250 kHz per channel. The results obtained from these tests revealed that the impact behavior of slabs differs significantly compared to their static behavior. Displacement profiles and force distributions are highly affected due to the high inertia forces during the impact.Master Thesis Nonlinear Finite Element Analysis of Reinforced Concrete Structures Subjected To Impact Loads(Izmir Institute of Technology, 2010) Cağaloğlu, Neriman Çare; Saatcı, Selçuk; Saatcı, SelçukDesign of reinforced concrete structures against extreme loads, such as impact and blast loads, is increasingly gaining importance. However, due to the problem.s complicated nature, there exists no commonly accepted methodology or a design code for the analysis and design of such structures under impact loads. Therefore, engineers and researchers commonly resort to the numerical methods, such as the finite element method, and utilize different methods and techniques for the analysis and design. Although each method has its advantages and disadvantages, usually engineers and researchers persist on their method of choice, without evaluating the performance of other methods available. In addition, there is no significant study in the literature comparing the methods available that can guide the engineers and researchers working in the area. This study compares the performance of some numerical methods for the impact analysis and design with the help from actual impact test results in the literature. Computer programs VecTor2 and VecTor3 were selected for nonlinear finite element methodology, which were based on the Modified Compression Field Theory. Impact tests conducted on reinforced concrete beams were modeled and analyzed using these programs. Moreover, same beams were modeled also using a single degree of freedom spring system method. The results obtained from both approaches were compared with each other and the test results, considering their accuracy, computation time, and ease of use.
