Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 5Citation - Scopus: 5Loop Based Classification of Planar Scissor Linkages(Springer, 2022) Kiper, Gökhan; Korkmaz, Koray; Gür, Şebnem; Yar Uncu, Müjde; Maden, Feray; Akgün, Yenal; Karagöz, CevahirScissor 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: 3Citation - Scopus: 3Çok Fonksiyonlu Form Değiştirebilir Köprü Tasarımı için İki Serbestlikli Strüktürel Mekanizma Önerisi(Gazi Üniversitesi, 2017) Gür, Şebnem; Yar, Müjde; Korkmaz, KorayHareketli köprüler ilk zamanlar korunma ihtiyacı ile tasarlanmıştır. Modern zamanlarda ise ulaşımıkolaylaştırmak için geliştirilmeye devam edilmektedir. Sabit köprülerin aksine farklı kullanım senaryolarınıdesteklemeleri sebebiyle tercih edilmektedirler. Bu yazıda mevcut hareketli köprüler kinematik özellikleriaçısından tanıtılmış, hangi kullanım seneryolarını destekledikleri ve eksik kaldıkları yönler açıklanmıştır.Daha sonra güncel bir örnek olan Rolling Bridge'de kullanılmış strüktürel mekanizmanın tasarım prensiplerden yararlanarak, tüm kullanım senaryolarını destekleyen form değiştirebilen köprü için çokdevreli ve iki serbestlikli yeni bir strüktürel mekanizma önerilmiştir. Son olarak mekanizmanın pozisyonanalizi yapılarak Microsoft Excel® ortamında gerçekleştirilen grafik sunulmuşturConference Object Citation - WoS: 3Citation - Scopus: 3Dynamic Shelter Structure(CRC Press, 2019) Maden, Feray; Ölmez, Duhan; Gür, Şebnem; Yar Uncu, Müjde; Mitropoulou, CharaDynamic building envelopes have entered the mainstream practice of architecture in the last decades. Such dynamic systems are capable of changing their geometric configurations repeatedly and reversibly relative to environmental conditions and occupant requirements. Thus, they may offer innovative building solutions by folding, expanding or curling. This study proposes a dynamic shelter structure that provides several shape options in response to the changing needs. In order to generate the shelter structure, first, loop assembly method used for developing the structure is introduced. Then, a parametric model is built in Grasshopper® not only to analyze the geometric properties of the loops and their alternative geometric forms but also to develop a flexible tool allowing changes at topological, geometrical and structural levels. Based on the geometric analysis, the structural mechanism is constructed. Transformation capability and possible configurations are studied. The proposed structure can transform itself into multiple forms (from planar configuration to S-shaped and reversed S-shaped configurations) with single DOF although the existing single DOF scissor structures can deploy between two geometric shapes. © 2019 Taylor & Francis Group, London.Conference Object Citation - WoS: 2Citation - Scopus: 2A Case Study on the Selection of Optimum Loop Units for the Deployable Arch Structures Exposed To Lateral and Non-Uniform Gravity Loads(Elsevier, 2020) Yuceturk, K.; Aktas, E.; Maden, F.; Gur, S.; Mitropoulou, C. C.Radially deployable arches may be created by using various types of units. However, for any deployable structure to be constructed in real life, it should satisfy the structural regulations and codes. Despite various advantages from architectural perspective, deployable structures are weak to satisfy the operational code limits when compared to trusses with similar height and span. Therefore, weight minimization is very important to reduce the dead loads of the structure which facilitates the code-conformance of the structure. The optimization of the deployable structures requires an initial selection of the loop types to define the structure parametrically. An initial selection strategy depending on the loads on the structure is important to increase the efficiency of optimization process. Under uniform gravity loads, optimum arrangement for each unit type converges to a similar point. However, in the real world, the loads on the arches are not always uniform and the structure is exposed to nonuniform loadings such as point loads or lateral loads. This work focuses on the performance of various arches with different unit types under lateral and non-uniform vertical loads. Different lateral load and non-uniform gravity loading scenarios are created. For each scenario, the arches with different units are analyzed. In all cases, clear span and height are kept as same. The performance of an arch with a specific unit type for a given load is measured with a score that includes the deformations and the weight of the structure. All the members are assumed to be circular hollow sections with variable diameter and thickness to have a meaningful weight comparison between structures. This work intends to define an initial selection guide for deployable arches under typical non-uniform and lateral loading conditions. (C) 2020 The Authors. Published by Elsevier B.V.Article Citation - WoS: 19Citation - Scopus: 20A 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, KorayWhen 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.Article Citation - WoS: 6Citation - Scopus: 5Design of Anti-Parallelogram Loop Assemblies(Int. Association for Shell and Spatial Structures, 2019) Gür, Şebnem; Korkmaz, Koray; Kiper, GökhanScissor 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: 1Citation - Scopus: 2Synthesis of Scalable Planar Scissor Linkages With Anti-Parallelogram Loops(Springer Verlag, 2019) Gür, Şebnem; Karagöz, Cevahir; Kiper, Gökhan; Korkmaz, KorayScissor 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.