Mechanical Engineering / Makina Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4129

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Now showing 1 - 7 of 7
  • Book Part
    Scherengestänge als elemente adaptiver morphologien
    (Birkhäuser, 2020) Akgün, Yenal; Maden, Feray; Gür, Şebnem; Kiper, Gökhan; Korkmaz, Koray; Aktaş, Engin; Yar Uncu, Müjde
    Zu allen Zeiten haben Menschen versucht, flexible Gebäude zu bauen, die sich ständig verändernden Anforderungen und Umweltbedingungen anpassen. Die Einbeziehung von Bewegung in die Architektur ist der Versuch, auf veränderliche Umstände mit neuen Lösungen zu reagieren. Das Konzept der Bewegung ist in der Tat nicht neu für die Architektur. Die Wurzeln gehen bis in die Antike zurück. Einfache, mit flexiblen Außenhäuten gebaute Nomadenzelte können als das erste Beispiel für adaptive Strukturen angesehen werden, die zum Schutz vor extremen Umweltbedingungen dienten.1 Die zum Abdecken des Daches im Colosseum von Rom verwendeten Leinwandbahnen sind ein weiteres Beispiel. Sie bildeten Markisen, die nicht nur Sonnenschutz boten, sondern für die Zuschauer durch ihr Durchhängen zur Mitte hin auch eine Brise einfingen.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Loop Based Classification of Planar Scissor Linkages
    (Springer, 2022) Kiper, Gökhan; Korkmaz, Koray; Gür, Şebnem; Yar Uncu, Müjde; Maden, Feray; Akgün, Yenal; Karagöz, Cevahir
    Scissor linkages have been used for several applications since ancient Greeks and Romans. In addition to simple scissor linkages with straight rods, linkages with angulated elements have been introduced in the last decades. In the related literature, two methods have been used to design scissor linkages, one of which is based on scissor elements, and the other is based on assembling loops. This study presents a systematic classification of scissor linkages as assemblies of rhombus, kite, dart, parallelogram and anti-parallelogram loops using frieze patterns and long-short diagonal connections. After the loops are replicated along a curve as a pattern, the linkages are obtained by selection of proper common link sections for adjacent loops. The resulting linkages are analyzed for their motions and they are classified as realizing scaling deployable, angular deployable or transformable motion. Some of the linkages obtained are novel. Totally 10 scalable deployable, 1 angular deployable and 8 transformable scissor linkages are listed. Designers in architecture and engineering can use this list of linkages as a library of scissor linkage topologies.
  • Article
    Citation - WoS: 19
    Citation - Scopus: 20
    A Critical Review on Classification and Terminology of Scissor Structures
    (Int. Association for Shell and Spatial Structures, 2019) Maden, Feray; Akgün, Yenal; Kiper, Gökhan; Gür, Şebnem; Yar, Müjde; Korkmaz, Koray
    When the existing literature on the research of scissor structures is thoroughly investigated, it is seen that different researchers use different terminologies and classifications especially for the definition of the primary units and the motion type. Some of the studies define the whole geometry based on the geometric properties of the primary scissor units and the unit lines while some other studies define it according to the loops. All these studies use different names for similar elements. This article aims to review the literature on the classification and terminology of scissor structures and represent the state of art on the studies. Tables are represented showing all approaches in the literature. In addition, the article criticizes the missing points of each terminology and definition, and proposes some new terminology. In order to arrive at this aim, different definitions of the primary scissor units and motion types used in key studies in the literature are investigated thoroughly. With several examples, it is demonstrated that naming the scissor units according to the resulting motion type might be misleading and it is better to specify the motion type for the whole structure. A classification for transformation of planar curves is presented.
  • Book Part
    Scissor Linkages in the Design of Adaptive Morphologies
    (Walter de Gruyter GmbH, 2019) Akgün, Yenal; Maden, Feray; Gür, Şebnem; Kiper, Gökhan; Korkmaz, Koray; Aktaş, Engin; Yar Uncu, Müjde
    Scissor linkages are capable of forming various expandable structures. Architects can benefit from this type of linkage especially for designing adaptive, movable, transformable shell structures and deployable beam-like structures. Product designers may benefit as well. The two different methods described here convey the basic design approaches. The unit-based method is very effective for obtaining primary geometries like a dome, arch, circle or line, using serial multiplications and arrays of one of the scissor unit types presented here. The loop assembly method is more convenient when a final form, be it straight or free-form, is the main point of departure. In this case, unlike in the unit-based method, it is not necessary to opt for a specific scissor unit type and its dimensional constraints from the beginning. Designers can choose a type and number of loops and then define the scissor units following the loop sides. Since deployability is guaranteed by applying this method, the architect is free to choose the loop type most suitable for the functional needs and aesthetic concerns of the specific design. With the loop assembly method all loop alternatives can be assembled to scissor structures, their possible motions can be tested and evaluated in a short time, whereas the unit-based method is limited to a single type of motion that a specific unit can provide.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 5
    Design of Anti-Parallelogram Loop Assemblies
    (Int. Association for Shell and Spatial Structures, 2019) Gür, Şebnem; Korkmaz, Koray; Kiper, Gökhan
    Scissor mechanisms are frequently used for deployable structures and many studies have been conducted on the subject. Most of the studies consider scissor units as modules in the design process. An alternative approach is to utilize loops as the modules for design. In this paper, the design alternatives of single degree-of-freedom planar linkages comprising anti-parallelogram loops using the loop assembly method is presented. First, scissor mechanisms are reviewed. Next, the types of four-bar loops and the resulting linkages in the literature are introduced and those which are yet to be explored, anti-parallelogram being one of them, are identified. Then the loop assembly method and the examples in the literature are reviewed. As a method to form as many alternatives as possible, symmetry operations are proposed. Suitable frieze symmetry groups utilized for obtaining the assemblies are explained and the anti-parallelogram loop patterns are derived. Next, the single degree-of-freedom linkages are obtained from the loop assemblies. Finally, a selection of the resulting linkages with novel properties are presented. This study shows that loop assemblies are efficient in systematic type synthesis of scissor linkages, some types of which could not be foreseen by using units as modules.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 2
    Synthesis of Scalable Planar Scissor Linkages With Anti-Parallelogram Loops
    (Springer Verlag, 2019) Gür, Şebnem; Karagöz, Cevahir; Kiper, Gökhan; Korkmaz, Koray
    Scissor linkages are commonly used as mechanisms for scaling objects. They constitute a significant portion of deployable structures. Since 1960s many researchers sought to form novel structures using the scissor units. In 1990s Hoberman brought a new perspective to the field when he used the loops, not the units to form linkages. Starting from mid 2000s, other researchers joined into this new approach of design. One of the latest researches presented a design for scaling a circular forms with anti-parallelogram loops. This study shows that an anti-parallelogram loop assembly can also be used for scaling planar curves with variable curvature.
  • Conference Object
    Radially Expandable Ring-Like Structure With Antiparallelogram Loops
    (Azerbaijan Technical University, 2017) Gür, Şebnem; Korkmaz, Koray; Kiper, Gökhan
    As they constitute a substantial percent of deployable structures, scissor mechanisms are widely studied. This being so, new approaches to the design of scissor mechanisms still emerge. Usually design methods consider the scissor elements as modules. Alternatively, it is possible to consider the loops as modules. In this paper, loop assembly method is used such that antiparallelogram loops are placed along a circle, to construct a deployable structure. The research shows that it is possible to construct radially deployable structures with identical antiparallelogram loops with this method. Then kinematic and geometrical properties of the construction are analyzed. It is found out that the links of such a structure turn out to be similar generalised angulated elements. Furthermore, similar loops are used for the construction and deployable rings are obtained.