Browsing by Author "Dinevari, Najmeh Faghih"

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Design of Self-Supporting Rotegrity Structure Using Notched Elements
(ASCE-AMER SOC CIVIL ENGINEERS, 2022) Najmeh Faghih Dinevari; Yaser Shahbazi; Feray Maden; Dinevari, Najmeh Faghih; Shahbazi, Yaser; Maden, Feray
Consisting of linear elements reciprocal frame structures are three-dimensional (3D) self-supported structures that can be rapidly assembled. This feature renders them suitable for both temporary and permanent uses. Considered as a type of deployable frame such structures can be used in architectural and engineering applications. As a subset of reciprocal frame structures rotegrity structures can be advantageous owing to their structural form. In this work a spherical rotegrity structure is constructed on a geodesic sphere through its transformation to a reciprocal structure with mutually supporting elements. Instead of the bolted connections commonly used in practice a notched connection is proposed to facilitate the construction process of the self-supporting rotegrity structure. The parametric modeling of the rotegrity structure is created in Grasshopper and two prototypes having circular and rectangular cross sections are built. In each prototype two sets of elements called Type A and Type B are used the linear member lengths and cross sections of which are identical. The cross sections of the members of the two prototypes are different. To assemble the prototypes first a number of elements are fabricated through 3D printing and tested in terms of their self-supporting capabilities and connections. Then stainless steel pipes and wooden bars are used for Prototypes I and II respectively. It is found that Prototype I composed of circular hollow section profiles is unstable owing to the rotation of elements and because it requires the use of stabilizers. Conversely Prototype II which consists of rectangular cross-section elements becomes stable when the last element is installed in the right place and did not require any additional attachment. (C) 2022 American Society of Civil Engineers.
Citation - WoS: 20
Citation - Scopus: 22
Geometric and analytical design of angulated scissor structures
(Elsevier Ltd, 2021) Najmeh Faghih Dinevari; Yaser Shahbazi; Feray Maden; Dinevari, Najmeh Faghih; Shahbazi, Yaser; Maden, Feray
Deployable scissor structures are capable of large geometric transformations between predefined configurations thanks to their extension and rotation properties. These structures are formed by connecting translational polar or angulated units that are composed of scissor-like elements. The studies especially on the angulated scissor structures mostly concentrate on developing certain types of planar or spatial structures, thus they do not present a systematic form-finding method for different types of angulated units lying on different path-curves. This paper aims to introduce two design methods including geometrical method based on drawings and analytical method based on mathematical equations both for generating various angulated scissor structures and facilitating the design of asymmetric and polycentric structures. First basic design principles of the angulated scissor structures are investigated. Then proper solutions are proposed to design such planar structures using both geometrical and analytical methods. Various planar angulated scissor structures are generated lying on monocentric and polycentric curves or straight-line in the deployed fully deployed and undeployed configurations. Finally a case study as a numerical model of a sunshade with monocentric curve is presented. © 2021 Elsevier B.V. All rights reserved.
Scissor Structures with Desired Path Expansion: Parametric Modeling and Optimization
(Birkhauser, 2025) Yaser Shahbazi; Najmeh Faghih Dinevari; Feray Maden; Dinevari, Najmeh Faghih; Shahbazi, Yaser; Maden, Feray
Transformed between predefined configurations designers can rapidly apply deployable scissor structures. By connecting successive points during movement—known as path generation– each point in a scissor structure follows a specific path. The path of a moving point is the geometric location of its successive positions defined by the structure’s geometry and support conditions. The path generation problem can be solved graphically or analytically where the graphical method offers a straightforward and convenient solution for simplified mechanisms. This article establishes a method for generating motion paths in scissor structures by integrating graphical analysis with an optimization technique. After defining path generation the path corresponding to the desired motion is determined and the structure is optimized to follow this target path. This path can then serve as a movement guide within the scissor structure. During optimization straight bars in the translational units are modified into angulated bars to meet deployability requirements. © 2025 Elsevier B.V. All rights reserved.