Phd Degree / Doktora

Permanent URI for this collectionhttps://hdl.handle.net/11147/2869

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2004 - 200912010 - 20202

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Subject: search.filters.subject.Structural design

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Now showing 1 - 3 of 3
  • Doctoral Thesis
    Manipulation of Structural Design Parameters To Mitigate the Concentrarion of Interstory Drift Ratios
    (Izmir Institute of Technology, 2020) Sönmez, Egemen; Dönmez, Cemalettin; Dönmez, Cemalettin
    Although the interstory drift ratio is used as a limiting factor for specific performance levels by the structural engineering profession, its distribution among the stories is generally disregarded. Observations and analytical studies have shown that even the structures are designed to conform seismic design codes, interstory drifts tend to concentrate at certain regions of the frame structures. In other words, the seismic demand the earthquake imposes is attempted to be provided from a limited part of the structure. As a result, the damage concentrates, and the stiffness of the corresponding stories decreases significantly. Locally, the story drifts become larger. Soft-story mechanisms and abrupt failures may occur under such conditions. In this study, a seismic design method was developed to control the distribution of interstory drifts in a frame structure during the nonlinear seismic response. This method is based on two observations: (i) in the inelastic range, the drift distribution is highly dependent on the yield strengths of the members; (ii) there is a strong correlation between the interstory drift distribution and the plastic rotation distribution at member-ends. Thus, an iterative design procedure is developed to control the distribution of the interstory drifts by adjusting the member yield strengths. Plastic rotations are used as a tool for estimating the required yield strengths. The efficiency of the proposed method was tested using nonlinear time-history analyses. The results demonstrated that the frames designed using the proposed method had well-distributed interstory drift and story damage patterns compared to those of the conventionally designed frames. Furthermore, the overall damage of frames was reduced remarkably.
  • Doctoral Thesis
    An Analytical Study of the Design Potentials in Kinetic Architecture
    (Izmir Institute of Technology, 2004) Korkmaz, Koray; Arkon, Cemal; Korkmaz, Koray; Arkon, Cemal
    This dissertation is concerned with the potentials of kinetic structures in architecture; what they are, what they can do for us, and how we can go about designing them. Ultimately, it aims at proving the applicability of kinematic methods in the design process of the adaptable space organizations by carrying out a personal design process of a novel kinetic structure. The course of this dissertation explores the ways in which kinematic synthesis methods contribute to the design processes of kinetic structures and adaptable spaces, which we call kinetic architecture.The idea of motion is not new. However, the concept of motion and its practical reflection appear more in end-products because of the dynamic, flexible, and constantly changing activities and developments in building technology. As a result of the rapid change in activities of modern society and developments in building technology, a need of the adaptable space emerged which was the necessary precondition for the rise of the concept of motion in architecture. This conceptual transformation may be dated to the end of the twentieth century. What marks the approach to the design of this new, late twentieth-century conception of space is 'motion', which will now play an increasingly important role both conceptually and in applications of design. Our capability of utilizing kinetics in architecture today can be extended far beyond what has previously been possible. The present dissertation describes kinematic analysis and synthesis methods used so far in mechanical engineering and explores its direct or in-direct applications into the architectural field.Arguing that the potential of kinetics in architecture remains far from fulfilled, it offers concrete direction and method for innovation. Focusing on responsive spatial adaptability and kinetic structures, it develops a foundation for the application of kinetic structures as a means of enhancing the performance of space. The motivation lies in creating adaptable spaces. There is a need for adaptable spaces and a design method for achieving this by building kinetic structures that can physically convert themselves through kinetics to adapt to the ever-changing requirements and conditions. This thesis proposes the use of kinematic methods in the design process of kinetic structures to create adaptable space organizations. In order to show the applicability of kinematic methods in the design process of the adaptable space organizations, a new type of an architectural umbrella covered by flexible material is developed for covering open-air spaces. Graphical synthesis method is used in the design process and the performance of the architectural umbrella is analyzed with Visual Nastran 4D. This is a CAD program capable of kinematic analysis.
  • Doctoral Thesis
    A novel transformation model for deployable scissor-hinge structures
    (Izmir Institute of Technology, 2010) Akgün, Yenal; Korkmaz, Koray
    Primary objective of this dissertation is to propose a novel analytical design and implementation framework for deployable scissor-hinge structures which can offer a wide range of form flexibility. When the current research on this subject is investigated, it can be observed that most of the deployable and transformable structures in the literature have predefined open and closed body forms; and transformations occur between these two forms by using one of the various transformation types such as sliding, deploying, and folding. During these transformation processes, although some parts of these structures do move, rotate or slide, the general shape of the structure remains stable. Thus, these examples are insufficient to constitute real form flexibility. To alleviate this deficiency found in the literature, this dissertation proposes a novel transformable scissor-hinge structure which can transform between rectilinear geometries and double curved forms. The key point of this novel structure is the modified scissor-like element (M-SLE). With the development of this element, it becomes possible to transform the geometry of the whole system without changing the span length. In the dissertation, dimensional properties, transformation capabilities, geometric, kinematic and static analysis of this novel element and the whole proposed scissor-hinge structure are thoroughly examined and discussed. During the research, simulation and modeling have been used as the main research methods. The proposed scissor-hinge structure has been developed by preparing computer simulations, producing prototypes and investigating the behavior of the structures in these media by several kinematic and structural analyses.