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.Conference Object Citation - WoS: 1Citation - Scopus: 2Structural Comparison of Scissor-Hinge Linkages(CRC Press, 2019) Maden, Feray; Akgün, Yenal; Yücetürk, Kutay; Aktaş, Engin; Yar Uncu, Müjde; Mitropoulou, C.Deployable structures can deploy from a compact to an expanded configuration by changing their sizes. The behaviors of these structures depend on some parameters such as geometric shape, member sizes and kinematic properties. To provide the deployment, not only the arrangements of structural members but also some restrictions must be considered. Moreover, contiguous members of the structures must let the large rotations to provide the transformation between different geometric forms from fully folded to fully deployed configurations. These requirements have an important impact on the fundamental properties of the structures related with structural performance, such as stiffness and strength. In this paper, stiffness of different scissor-hinge linkages are analyzed and compared. These linkages cover the same span with almost the same geometry and have the unit elements with same size and same weight. However, the geometry of unit elements is different from each other. The paper investigates the effect of this difference on the stiffness of whole system. © 2019 Taylor & Francis Group, London.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 - Scopus: 11A Novel Planar Scissor Structure Transforming Between Concave and Convex Configurations(WITPress, 2017) Yar, Müjde; Korkmaz, Koray; Kiper, Gökhan; Maden, Feray; Akgün, Yenal; Aktaş, EnginIn this paper, a novel two-dimensional scissor structure that transforms between concave and convex configurations is presented. The structure is designed by a method of assembling kite or anti-kite loops in the flat configuration. Angulated units are generated from the assembled loops. Finally, a new angulated scissor unit is introduced in order to design the novel scissor structure.Conference Object Citation - WoS: 3Citation - Scopus: 3Design of Adaptive Structures by Kinematic Synthesis of Mechanisms(CRC Press, 2013) Akgün, Yenal; Maden, Feray; Korkmaz, KorayParallel to the development of material science and computer technologies, adaptive structures and smart building components have become the demand of contemporary architecture. However, in order to design adaptive systems, basic knowledge on kinematic synthesis is needed. This paper introduces the fundamental principles of the kinematic synthesis of mechanisms and expresses the potential structural uses of common mechanisms. For this purpose, main concepts of the mechanisms are introduced and types of kinematic synthesis are explored by the help of innovative examples. In this context, firstly, type synthesis methods are explained. Second step covers the path generation rules, and the final step includes the design of multi-loop and chain mechanisms. During the explanation of the aforementioned principles, innovative adaptive structures which are designed by the authors are introduced as well. These structures are all derived from common planar and spatial mechanisms such as four-bar linkages, Watt mechanisms, scissor systems, Bennett linkages and different multi-loop mechanisms.Conference Object Citation - Scopus: 2Design of Reconfigurable Doubly-Curved Canopy Structure(CRC Press, 2013) Maden, Feray; Korkmaz, Koray; Akgün, YenalIn this paper, a new reconfigurable doubly-curved structure has been developed for a canopy roof. The proposed structure can transform itself to various configurations according to the activity and user requirements. It not only changes its shape from a planar geometry to doubly-curved geometries by means of actuators, but also becomes stable and carries loads. The main differences between proposed structure and similar deployable bar structures are that the proposed structure is more flexible with 2DoF and it requires less number of bars and joints. To obtain the doubly-curved geometry, a novel method has been introduced. After discussing the kinematic behavior of the system, a set of structural analyses are performed in three different geometric configurations of the proposed structure.Article Citation - WoS: 89Citation - Scopus: 118A Novel Adaptive Spatial Scissor-Hinge Structural Mechanism for Convertible Roofs(Elsevier Ltd., 2011) Akgün, Yenal; Gantes, Charis J.; Sobek, Werner; Korkmaz, Koray; Kalochairetis, Konstantinos E.In this paper, a new adaptive deployable spatial scissor-hinge structural mechanism (SSM) is introduced, which can be converted by means of actuators between a multitude of arch-like, dome-like and double curved shapes, where it can be stabilized and carry loads. This novel SSM is a spatial extension of a planar SSM introduced recently that can achieve a wide range of planar geometries. Main differences of the proposed structural mechanism from current deployable structures are the new connection type of the primary units and the proposed modified spatial scissor-like element (MS-SLE). With the development of this new connection detail and the modified element, it becomes possible to change the geometry of the whole system without changing the dimensions of the struts or the span. After presenting some disadvantages of current deployable structures and outlining the main differences of the proposed spatial SSM with existing examples, the dimensional properties of the primary elements are introduced. Then, geometric principles and shape limitations of the whole structure are explained. Finally, structural analyses of a typical structure in two different geometric configurations are performed, in order to discuss stiffness limitations associated with the advantage of increased mobility.Article Citation - WoS: 75Citation - Scopus: 95A Review of Planar Scissor Structural Mechanisms: Geometric Principles and Design Methods(Taylor and Francis Ltd., 2011) Maden, Feray; Korkmaz, Koray; Akgün, YenalThis study deals with a review of planar scissor structural mechanisms (SSMs) and reports on how they can be easily transformed from a stowed to a deployed configuration. These mechanisms have an important transformation capacity of their extension and rotation properties, and many examples have been proposed that vary in size, type and geometry. Although there are many studies dealing with designing new planar or spatial SSMs and their calculation methods, there is no systematic study demonstrating the basic typologies, geometric principles, design rules and constraints of such SSMs. Further, current calculation methods are based on the inductive approach in which the dimension of one scissor unit (SU) is given, but the span of the whole structure is found later according to the number of SUs that are used to assemble the structure. However, this approach is not convenient for architectural applications, because it requires a deductive approach in which the dimensions and required number of SUs are calculated according to defined span length. On the basis of this concept, this article, first, analyses the geometric design of SSMs systematically in terms of their possible configurations and then develops trigonometric calculation methods for different types of SSMs, using a deductive approach.Article Citation - WoS: 16Citation - Scopus: 17Design of a 2-Dof 8r Linkage for Transformable Hypar Structure(Taylor and Francis Ltd., 2012) Korkmaz, Koray; Akgün, Yenal; Maden, FerayDouble curved geometries including hyperbolicparaboloids (hypars) have become a trend in contemporary architecture. However, most of the constructed architectural examples of the hypars are static and cannot offer any form variability. In this paper, a 2-DOF 8R linkage mechanism is introduced to buildtransformable hypar structures. It is inspired from the basic design principles of Bennett linkage. By its distinctive connection details and additional links, this novel mechanism can change its form fromplanar geometries to various hypars. The paper begins with the brief summary of the applications of hypar structures in architecture. Secondly, main principles and deficiencies of the Bennett linkage are presented. According to these deficiencies, structural synthesis of the novel mechanism is considered. Finally, advantages and potential uses of the proposed novel mechanism are explained. © 2012 Copyright Taylor and Francis Group, LLC.Article Citation - WoS: 59Citation - Scopus: 66A Novel Concept of Convertible Roofs With High Transformability Consisting of Planar Scissor-Hinge Structures(Elsevier Ltd., 2010) Akgün, Yenal; Gantes, Charis J.; Kalochairetis, Konstantinos E.; Kiper, GökhanIn this paper, a new adaptive scissor-hinge structure is introduced, which can be converted by means of actuators between a multitude of curvilinear arch-like shapes, where it can be stabilized and carry loads. The key point of this new structure is the proposed Modified Scissor-Like Element (M-SLE). With the development of this element, it becomes possible to change the geometry of the whole system without changing the dimensions of the struts or the span. The proposed scissor-hinge structure discussed here is planar, but it is also possible to combine structures in groups to create spatial systems. After outlining the differences of the proposed structure with existing designs, the dimensional properties of the M-SLE are introduced. Then, geometric principles and shape limitations of the whole structure are explained. Finally, structural analysis of the structure in different geometric configurations is performed, in order to discuss stiffness limitations associated with the advantage of increased mobility. © 2010 Elsevier Ltd.