Mechanical Engineering / Makina Mühendisliği

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

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  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Design of Demountable Reciprocal Frames With New Geometric Properties
    (Int. Association for Shell and Spatial Structures, 2022) Özen, Gülçin; Kiper, Gökhan; Korkmaz, Koray
    This study aims to develop missing geometric knowledge for demountable reciprocal frames (RF). While designing a demountable RF, one should know the initial, in-process and final form of the RF. These processes require some specific geometric knowledge. There are some deficiencies about geometric properties in the previous studies about demountable RFs. In this study, the positions and the orientations of the nexors are found by using the Denavit-Hartenberg parameters. This information gives where the joints are placed, how they are oriented and take position according to one another. Besides, the influence of engagement length on the fan height and the base edge are analyzed. Thereby one will be able to find out how much space the RF covers with the known base edge. With the geometric knowledge obtained from this study, demountable RFs having different engagement lengths can be produced with the same nexors.
  • Article
    A Novel Design Method of Deployable Semi-Regular Tessellated Surfaces With Plano-Spherical Units
    (Int. Association for Shell and Spatial Structures, 2022) Maral, Mesude Oraj; Korkmaz, Koray; Kiper, Gökhan
    The design of movable systems gives an opportunity to create transformable designs which respond to the environmental, functional, cultural, and aesthetical needs of today's architecture. This paper proposes a method for designing a family of deployable structures which can be applied to semi-regular tessellated planar surfaces such as roofs, walls, and shading devices. The generated modular approach and adaptability provides a wide usage area and various combinations for these designs. The regular convex polygon modules are designed as a network of the triangular units. The triangular unit is designed using Bennett's overconstrained plano-spherical linkage topology. The polygonal modules are assembled to each other in one-uniform semi-regular tessellations. The assembly of adjacent regular convex polygons in each tessellation is examined to find a proper solution for no collision during deployment and to properly fit a surface without any gaps or overlaps in the deployed position. The assembly method for creating 1-DoF deployable surfaces and mobility calculations for a unit, the polygonal modules, and the assemblies are computed, and motion studies are demonstrated with CAD models and exemplified for a square module for motion tests in a prototype.
  • Article
    Design, Prototyping and Tests of a Rollable Ramp for Temporary Use
    (Springer, 2021) Doğan Kumtepe, Elvan; Kiper, Gökhan
    Portable ramps, used generally by wheelchair users, offer temporary solution to increase accessibility and mobility. Preferably these ramps should be compact and lightweight for ease of handling and storage. Different types of portable ramps in the market that are used by wheelchair users are generally made of aluminum and require several improvements, especially in terms of lightweight and compactness. Based on wheelchair users’ inclinations a compact and lightweight rollable ramp is designed in this study. A parametric model of the links of the ramp are derived and the rolled geometry is optimized using convex hull and smallest enclosing circle algorithms. The side bars of the links are designed and manufactured from aluminum and the load-bearing panels are manufactured from sandwich composite structures with honeycomb core. Strength calculations are performed analytically and also with finite-element analysis. After the design is finalized, a prototype is manufactured. The designed ramp is 15.4% more compact and has 18.9% less weight compared to the best rival product available in the market. Load tests and functional tests are performed with voluntary wheelchair users. Several positive feedbacks are received from the participants about the ramp being practical, easy to use and store, lightweight, advantage of the anti-slip surface.
  • Conference Object
    A sustainable association case study: IFToMM member organization Turkey
    (Springer, 2022) Kiper, Gökhan; Söylemez, Eres
    As a member of IFToMM founded in 2011, Turkish Machine Theory Association’s (MakTeD) structure has put special emphasis on sustainability of the association and initiated several activities for improving the quality of education and research in mechanism and machine science area, hence supporting the SDG4 Quality Education of the UN. This paper presents the activities and methodologies of MakTeD. The paper starts with a brief history of mechanism and machine science in Turkey. In 10 years MakTeD organized 4 symposiums, 1 conference, 4 summer/winter schools, 8 workshops and hosted an IFToMM Executive Council meeting. Each chapter of the biyearly held National Symposium on Theory of Machines is held by a different university and especially newly established and the universities in relatively smaller cities are prioritized in order to promote those universities and to contribute to development of these universities. Especially the summer/winter schools and workshops have a widespread impact on mechanism and machine science education and research at the universities and institutions. MakTeD also contributes to the community with published books and support programs for young researchers.