• Title/Summary/Keyword: tensegrity

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A Form-finding of Planar Tensegrity Structures

  • Lee, Sang Jin
    • Architectural research
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    • v.14 no.4
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    • pp.143-152
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    • 2012
  • A form-finding procedure is presented for planar tensegrity structures. Notably, a simple decision criteria is proposed to select the desirable candidate position vector from the unitary matrix produced by the eigenvalue decomposition of force density matrix. The soundness of the candidate position vector guarantees faster convergence and produces a desirable form of tensegrity without any member having zero-length. Several numerical examples are provided to demonstrate the capability of the proposed form-finding process.

A Design Method of Tensegrity Units for Renovation Elements (리모델링 부재 적용을 위한 텐세그리티 유닛 설계기법)

  • Lee, Seung-Hye;Lee, Jaehong;Jung, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.17 no.4
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    • pp.141-148
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    • 2017
  • In this study, an advanced form-finding method of tensegrity unit modules is presented to apply on renovation building. Here a fitness function of maximum natural frequency which can lead to a maximum stiffness status was used for a genetic algorithm. To apply the lightweight pin-jointed structure to the renovation project is more economical over to build new structures. In this paper, two types of tensegrity unit are presented to build expanded structures, and their force densities are shown using the proposed form-finding method. The expanded structures which may influence renovation projects are presented by using the tensegrity units.

A Study on the Unstable Characteristics of Tensegrity Cable Domes According to Loading Conditions (하중조건에 따른 Tensegrity 케이블 돔의 불안정 거동 특성에 관한 연구)

  • Baek, In-Seong;Jeong, Eul-Seok;Kim, Seung-Deog
    • Proceeding of KASS Symposium
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    • 2005.05a
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    • pp.161-166
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    • 2005
  • In spatial structures with large spaces, one important issue in structures with large spaces is how to carry the weight of the roof. A tensegrity cable dome structure is a kind of soft structural system using the tension cable and compression column as a main element. The tensegrity cable dome is built into a variety of shape around the world but then a collapse accident is increasing. Owing to a collapse accident we must grip of the collapse mechanism to prevent an accident and construct the structure with safety and economy. In this study, I investigated the unstable characteristics of the Geiger-type and Flower-type tcnsegrity cable dome structures, which is the lightweight hybrid structures using compression and tension elements continuously, according to the difference of loading conditions.

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Deformation Measuring of Tensegrity Structure by Optical Fiber Bragg Grating Sensor (광섬유 브래그 격자 센서를 이용한 텐서그리티 구조물의 변형 계측)

  • Lee, Seung-Jae
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.6
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    • pp.95-100
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    • 2008
  • The object of this paper is to verify possible to monitor the deformation of cable in the tensegrity structure. Also, always monitoring system of tensegrity structure using Fiber Bragg Grating Sensor is described. We carry out experiments with measuring deformation of cable in the tensegrity structure based on loading conditions. In the result of experiment, the Fiber Bragg Grating Sensors shows accurate response to the loading conditions. Therefore, we can make sure the possibility of Fiber Bragg Grating Sensor in health monitoring of the cable structure like tensegrity structure.

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Dismountable steel tensegrity grids as alternate roof structures

  • Panigrahi, Ramakanta;Gupta, Ashok;Bhalla, Suresh
    • Steel and Composite Structures
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    • v.9 no.3
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    • pp.239-253
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    • 2009
  • This paper reviews the concept of tensegrity structures and proposes a new type of dismountable steel tensegrity grids for possible deployment as light-weight roof structures. It covers the fabrication of the prototype structures followed by their instrumentation, destructive testing and numerical analysis. First, a single module, measuring $1m{\times}1m$ in size, is fabricated based on half-cuboctahedron configuration using galvanised iron (GI) pipes as struts and high tensile stranded cables as tensile elements. Detailed instrumentation of the structure is carried out right at the fabrication stage. The structure is thereafter subjected to destructive test during which the strain and the displacement responses are carefully monitored. The structure is modelled and analyzed using finite element method (FEM) and the model generated is updated with the experimental results. The investigations are then extended to a $2{\times}2$ grid, measuring $2m{\times}2m$ in size, fabricated uniquely by the cohesive integration of four single tensegrity modules. After updating and validating on the $2{\times}2$ grid, the finite element model is extended to a $8{\times}8$ grid (consisting of 64 units and measuring $8m{\times}8m$) whose behaviour is studied in detail for various load combinations expected to act on the structure. The results demonstrate that the proposed tensegrity grid structures are not only dismountable but also exhibit satisfactory behaviour from strength and serviceability point of view.

A Comparison of the Form-Finding Method of Tensegrity Structures (텐세그리티 구조물의 형상탐색 기법 비교)

  • Lee, Seunghye;Lee, Jaehong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.4
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    • pp.313-320
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    • 2014
  • A tensegrity structure consists of a set of continuous cables in tension and a set of discontinuous struts in compression. The tensegrity structure can be classified into self-stressed and pre-stressed pin-jointed structure. A key step in the design of tensegrity structures is the determination of their equilibrium configuration, known as form-finding. In this paper, three effective methods are presented for form-finding of tensegrity structures. After performing form-finding process, a set of force density and corresponding topology results can be obtained. Then the force density method combined with a genetic algorithm is adopted to uniquely define a single integral feasible set of force densities. Numerical examples are presented that demonstrate the excellent performance of the algorithms.

Linear Form Finding Approach for Regular and Irregular Single Layer Prism Tensegrity

  • Moghaddas, Mohammad;Choong, Kok Keong;Kim, Jae-Yeol;Kang, Joo-Won
    • International journal of steel structures
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    • v.18 no.5
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    • pp.1654-1665
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    • 2018
  • In an irregular prism tensegrity, the number of force equilibrium equations is less than the number of unknown parameters of nodal coordinates and member force ratios. As a result, the form-finding process normally becomes nonlinear with additional conditions or needs to be carried out with the use of iterative procedures. For cases of irregular prism tensegrity which involves large number of members, it was found that previously proposed methods of form-finding are not practical. Moreover, there is a need for a form-finding approach which is able to cater to different requirements on final configuration. In this paper, the length relation condition is introduced to be used in combination with the force equilibrium equation. With the combined use of length relation and equilibrium conditions, a linear form-finding approach for irregular prism tensegrity was successfully formulated and developed. An easy-to-use interactive form-finding tool has been developed which can be used for form-finding of irregular prism tensegrities with large number of elements as well as under diverse specific requirements on their configurations.

Form-finding of Tensegrity Systems by using Frequency Constraints (진동수 목적함수를 이용한 텐세그리티 시스템의 형상탐색기법)

  • Lee, Seung Hye;Lee, Jae Hong;Kang, Joo Won
    • Journal of Korean Society of Steel Construction
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    • v.28 no.5
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    • pp.337-344
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    • 2016
  • In this study, a form-finding method of tensegrity systems by using the force density method combined with the stiffness matrix method was presented. Numerous studies have been made on form-finding methods of the tensegrity systems. However, these methods are limited in the tensegrity systems with multiple null space of the equilibrium matrix. The proposed method can uniquely define a single integral feasible set of force densities for the structures. In order to draw maximum natural frequency that can lead a maximum stiffness of the tensegrity systems, a constrained maximization problem is formulated in the genetic algorithm. Several numerical examples are presented to prove dfficiency in searching for self-equilibrium congifurations of tensegrity systems with multiple self-stress states. A good performance of the proposed method has been shown in the results.

A Study on Reformability and Application of Tensegrity Modules (텐서그러티 모듈의 변형 및 응용에 관한 연구)

  • Choi, Sun-Young;Park, Sun-Woo;Park, Chan-Soo
    • Journal of Korean Association for Spatial Structures
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    • v.5 no.2 s.16
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    • pp.73-79
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    • 2005
  • Tensegrity is a relatively new structural system based on the use of continuous tension-discontinuous compression. Of course, a much more detailed structural investigation would be necessary, but at least in order to achieve the intended purpose, it is essential to understand the structural principles and the fundamental forces of tensegrity. Once this point is established, the applications of them to architecture are described, as well as the characteristics of these structures. Then, in spite of the controversial definitions to explain these systems, several examples of tensegrity prototypes or modules constructed in iESD(Institute of Environmental Structure Design) are presented to illustrate the feasibility of tensegrity as a lightweight structure. In this work, consequently, the reformability and application of tensegrity modules have also been researched in architecture, after the patterns of basic module as well as fundamental definition are introduced.

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Form-finding of Tensegrity Structures with constraints by using Force Method (하중법을 이용한 텐세그리티 구조물의 자기평형 응력 탐색)

  • Chung, Woo-Sung;Lee, Jae-Hong;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.11 no.4
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    • pp.49-59
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    • 2011
  • This paper presents a new numerical method by using Singular Value Decomposition force method for form-finding of tensegrity structures with constraints. In order to maintain the tensegrity structures stable, state of self-equilibrium stress should be introduced. The existing force method has some advantages about form-finding of tensegrity structures. However, this method has complex formulation. In force density method, dummy members are required for form -finding of tensegrity structures with constraints. Therefore this study proposes new force method using Singular value decomposition. The proposed method is both having easy basic consept and simple computation than existing force method. A numerical example is presented to demonstrate the efficiency and robustness in searching initial single integral feasible self-stress mode for tensegrity structures with constraints.