Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis The Structural Conservation Problems of Traditional Houses in Eryeri, Mardin, Artuklu(01. Izmir Institute of Technology, 2023) Ercan Gündüz, Yasemin; Turan, Mine; Aktaş, EnginThe aim of this study is to document the construction techniques, material usage, and structural failures of the traditional houses in a village of Mardin, Eryeri, in order to guide a conservation aimed development plan that will be prepared in the future and enhance the related rehabilitation implementations. Eight houses that have preserved their authenticity were selected. Field survey focusing on the structural elements such as foundations, walls, floors, and roofs was conducted with the conventional techniques of architectural restoration. Both failures and also alterations of the buildings were documented. The changes and alterations of the houses are documented. Visual analysis of the constructional qualities was made with Archicad23 tools. Comparison with the traditional houses in the vicinity was made with reference to data gathered via field survey, literature review and archive research. As a result, the traditional houses are integrated with the rocky terrain of the region and in masonry system. There is an intense use of local stone, Yellow Limestone. Vaults are common superstructure elements, but timber floor is also possible. The walls are stone masonry in all. The common structural problems are demolition of structural elements such as roofs. The causes of severe failures are neglect and natural aging. The reinforced concrete additions flanking to the authentic structures also cause failure. Within the scope of the conservation plan, it is important to prevent reinforced concrete annexes and to intervene the annexes that cause excessive loads urgently.Master Thesis Application of Artificial Neural Networks To Structural Reliability Problems(01. Izmir Institute of Technology, 2023) Köroğlu, Fahri Baran; Aktaş, Engin; Maguire, MarcThe contemporary approach in structural engineering indirectly addresses uncertainties arising from load and resistance parameters by using safety factors. To consider these uncertainties in structural engineering, it is necessary to incorporate their statistical properties into the analysis and design process. However, this approach requires the calculation of challenging multi-fold probability integrals. Approximate methods known as FORM and SORM have been developed as an alternative to calculating those integrals. Unfortunately, these methods might have accuracy and convergence problems depending on the problem at hand. Simulation-based structural reliability methods have been developed to overcome the problems associated with approximate methods. The main problem with these methods is that they are often computationally expensive when along with finite element analysis, or it is hard to implement them when a more specific method is chosen to reduce computational costs. In this study, artificial neural networks have been applied to structural reliability problems to obtain accurate probability estimates with low computational cost. A special type of learning algorithm called Bayesian Regularization was used in the training of artificial neural networks. Additionally, details of the application of artificial neural networks to structural reliability problems are provided. At the end of the study, the advantages and disadvantages of applying artificial neural networks to structural reliability problems are presented and compared with other known structural reliability methods. Additionally, a new convergence criterion and an adaptive algorithm have been developed. It was observed that applying artificial neural networks to structural reliability problems provides both efficient and accurate probability estimates.Master Thesis A Practical Finite Element Model of Tsadwa Type Semi-Rigid Connections for Push-Over Analysis of Steel Frames in Sap2000(01. Izmir Institute of Technology, 2021) Şeker, Öncel; Aktaş, EnginIn steel structural analyses, beam to column connections is traditionally fully pinned or fully rigid. In the analysis assumption, moment (rigid) connections are assumed not to undergo rotation, and shear (pinned) connections can't transfer moment. These classifications do not represent actual connection behavior. Moment (rigid) connections have some relative flexibilities to rotate, and shear (pinned) connections have some capacity to transfer moment. In the light of these actual connection capabilities, another type of connection called partially restrained (PR) or semi-rigid connection is introduced. This study focuses on the behavior of bolted top, and seat angle with double web angle (TSADWA) connection using finite element method (FEM) software (ANSYS) to obtain moment-rotation curves, including geometrical and mechanical properties of the connection and adaptation of the PR connection behavior into the planar frame is performed for performance analysis through SAP2000 software by considering current codes and literature. Azizinamini's (Azizinamini, 1985) experimental and Frye and Morris's (Frye & Morris, 1975) mathematical moment-rotation curves are used to compare with the curves produced in the ANSYS to validate the feasibility of the finite element based PR connection models. A portal frame model with an 8S10 PR connection in the SAP2000 for performance analysis is also compared with the ANSYS portal frame model to demonstrate the correlation between the push-over analysesto reduce the margin of error. Although there is a lack of experimental information on the TSADWA connected frame models, results show that semi-rigid connection models and their usage on the steel frames can propose a reliable and practical methodology for the analysis process.