• Title/Summary/Keyword: Tensegrity

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A Study on the Optimal Initial Stress-Finding of Structures Stabilized by Cable-Tension (장력안정 구조물의 최적초기응력 탐색에 관한 연구)

  • 최옥훈;한상을;권택진
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.04a
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    • pp.287-294
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    • 1999
  • The tensegrity structure by prestressed cable, which may have large freedom in scale and form and therefore are received much attention from the view points of their light weight and aesthetics, is a very flexible and geometrically unstable structure because the cable material has little initial rigidity. For the stable self-equilibrated state of the usually very deformable structure, the method to find the optimal initial stress by the shape analysis is proposed in this paper. The proposed procedure is to derive the nonlinear finite element formula of cable and truss members considering geometric nonlinearity and used to modified load incremental method adding to Newton-Raphson method with the proposed condition for optimal initial stress. The result of the shape analysis for the tensegrity structure with the radius of 30m is shown the almost approximated shape to architectural shape and the changed procedure of initial stress

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A Study on the Stress Control Technique of Tensegrity Structures (Tensegrity구조물의 장력제어 기법에 관한 연구)

  • 김승덕;정을석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.285-292
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    • 2003
  • The soft structure can make large space more effectively, and its construction is easy and simple as well. However, it is not easy to realize this in the actual space. Therefore, two works are needed to be done for effective and accurate construction of soft structures. First, making a working scenario to complete the final objective form; second revising construction errors occurred in the middle of the actual works. These works are called constructional analysis. At this time, geometric nonlinearity should be considered to reflect the sensitivity by the initial stress of flexible structures, constructional analysis comes down to a nonlinear problem after all. This study approaches nonlinear constructional analysis with the numerical method for adjusting stress of cable-dome structures which are a soft structure system, and then verifies it.

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Design of Compliant Hinge Joints inspired by Ligamentous Structure (인대 구조에 기인한 유연 경첩 관절의 설계)

  • Lee, Geon;Yoon, Dukchan;Choi, Youngjin
    • The Journal of Korea Robotics Society
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    • v.14 no.4
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    • pp.237-244
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    • 2019
  • This paper suggests novel types of joint mechanisms composed of elastic strings and rigid bodies. All of the human hinge joints have the articular capsule and a pair of collateral ligaments. These fibrous tissues make the joint compliant and stable. The proposed mechanism closely imitates the human hinge joint structure by using the concept of tensegrity. The resultant mechanism has several characteristics shown commonly from both the tensegrity structure and the human joint such as compliance, stability, lightweight, and non-contact between rigid bodies. In addition, the role and feature of the human hinge joints vary according to the origins of a pair of collateral ligaments. Likewise, the locations of two strings corresponding to a pair of collateral ligaments produce different function and motion of the proposed mechanism. It would be one of the advantages obtained from the proposed mechanism. How to make a joint mechanism with different features is also suggested in this paper.

Forearm Mechanism Inspired by Ligamentous Structure and Its Mobility Analysis (인대 구조에서 기인한 전완 메커니즘과 자유도 해석)

  • Lee, Geon;Lee, Ho
    • The Journal of Korea Robotics Society
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    • v.17 no.2
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    • pp.209-215
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    • 2022
  • In this paper, a forearm Mechanism design inspired by ligamentous structure of the human body is proposed. The proposed mechanism consists of four rigid bodies and fourteen wires without any mechanical joints. Actually, the mechanism is based on the concept of the tensegrity structure. Therefore, the proposed mechanism has inherently compliant characteristics due to the flexibility of the wires composing the structure. Rigid bodies and wires of the mechanism mimic bones and major ligaments in the forearm of the human. The proposed mechanism is classified as one of the interconnected hybrid flexure systems. The analysis method of the degree of freedom (DOF) of the proposed mechanism is also introduced through analyzing technique of the interconnected hybrid flexure systems, in this paper. Ultimately, the proposed mechanism, whose structure is complicated with rigid bodies and wires, mathematically drives that it has 3-DOFs.

A Study on the Shape Analysis of Cable-Dome Structures (케이블-돔 복합구조의 형상해석에 관한 연구)

  • 권택진;한상을;최옥훈
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.93-100
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    • 1998
  • The basic systems of spatial structures such as shells, membrane, cable-nets and tensegrity structure have been developed to create the large spaces without column. These structures may have large freedom in scale and form, and especially tensegrity structures are received much attention from the view points of their light weight and aesthetics. But There re some difficulties concerning structural stability, surface formation and construction method. One of the way to solve these problems reasonably is a combination of tensile members and rigid members. A structural system based on this concept is referred to as the "HTS ( Hybrid Tension Structure )". This is a type of flexible structural system which is unstable initially, because the cable material has little initial rigidity. As cable - dome hybrid structures is a type of HTS, the initial stress for the self- equilibrated system having stable state have to be introduced. To determine initial stress having stable state, the shape finding analysis is required before the stress - deformation analysis. In this paper, the primary objective is to derive the nonlinear finite element formula of cable and truss members considering geometric nonlinearity for shape finding of cable-dome, and to propose the method to decide the initial stress by the shape analysis of cable-dome hybrid structure with the self-equilibrated state.

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Mechanical Characteristics of Cable Truss Roof Systems (케이블 트러스 지붕 시스템의 역학적 특성)

  • Park, Kang-Geun;Lee, Dong-Woo
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.2
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    • pp.89-96
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    • 2016
  • Cable structures are lightweight structures of flexible type, cable members have only axial stiffness related to tension, they can carry neither bending nor compression. This study is the analysis of cable truss systems are composed of upper and low cables by connecting bracing cables, the structural principle is based on a tensegrity system by using bracing tension members, discontinuous compression members and continuous tension members. A hanging roof of cable truss system is too flexible against vertical loads, most cable members are stabilized by connecting the prestressed upper and lower cable by bracing cables. A cable truss roof system is formed by adding a set of cables with reverse curvature to the suspension cables. With the sets of cables having opposite curvature to each other, cable truss is able to carry vertical load in both upward and downward direction with equal effectiveness, and then a cable truss acts as load bearing elements by the assemble of ridge cables, valley cables and bracing cables. This paper will be shown the geometric non-linear analysis result of cable truss systems with various sag ratio for deflections and tensile forces, the analytical results are compared with the results of other researchers.

HYBRID LIGHTWEIGHT STRUCTURES -On Recent Projects aimed at Holistic Design

  • Saitoh, Masao
    • Proceeding of KASS Symposium
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    • 2005.05a
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    • pp.52-66
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    • 2005
  • Tension and Membrane have the potential to enable the realization of lightweight structures that have the attractive features of structures efficiency and aesthetical expression. Compared with pure (thorough-bred) tension structures such as cable net, air dome and tensegrity, so called hybrid tension structures such as beam string, tensegric system and other mixed structures have Potential still to be realized. After synnaruzubg the simple definition of tensegric structure, some holistic designs for hybrid tension structures completed recently in the author's practice are given.

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A Study on the Theory and Application for the Morphological Aspects of Hybrid Spatial Structures (대공간구조물의 형태결정에 관한 이론 및 응용에 관한 연구)

  • 이경수;이상주;유용주;한상을
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.272-279
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    • 1998
  • The purpose of this study is to show how to gain the morphology of the Hybrid Spatial Structures and to get the geometrical data such as node coordinates, member relationships and graphic images. To form spatial structures, we have developed morphological aspects of general spatial structures, programming process and techniques. Structural design has many processes. Especially, it is very important to consider the determination of structural configuration. Regular Hybrid Spatial Structures have complex configuration, so we need to make use of automated computer process to determine structural shape in Hybrid Spatial Structures. We have applied morphological aspects to double layer plate, single layer dome, double layer dome and tensegrity structure.

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Form-Finding of Tensegrity Structures based on Eigenvalue Formulation (고유치문제에 근거한 텐세그러티 구조물의 형상탐색)

  • Jung, Mi-Roo;Kim, Jong-Su;Baek, Ki-Youl;Lee, Jae-Hong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2010.04a
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    • pp.584-587
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    • 2010
  • 본 논문에서는 고유치문제에 근거한 텐세그러티 구조물의 형상탐색에 대하여 제시하고자 한다. 하지만 자기평형 응력을 구하기 위해서 정방형 행렬이 아닌 장방형 행렬을 풀어야 하는 난제가 발생하므로 선행 연구자들은 이를 해결하기 위해 내력밀도법과 일반역행렬을 이용한 방법 등을 제시하였다. 본 연구에서는 새롭게 형상을 탐색하는 방법을 제시하여 텐세그러티 구조물 및 케이블 돔 구조물의 자기평형 응력을 얻었다. 제시한 방법은 기존의 방법을 기본으로 한 모든 절점의 평형 방정식을 고유치문제로 정식화하였다. 이를 증명하기 위해 몇 가지 예제에 대하여 수치해석을 수행하였고 타당성을 검증하기 위하여 기존의 방법과 비교하였다. 제시된 방법은 기존의 방법과 같은 결과가 나왔으며 해답을 얻는 과정이 훨씬 간단하였다.

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