• Title/Summary/Keyword: self-equilibrium stress mode

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A Numerical Analysis Approach for Design of Cable Dome Structures (케이블 돔 구조물 설계를 위한 수치해석 방법)

  • Kim, Jae-Yeol;Jang, Dong-Woo
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.89-94
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    • 2008
  • This paper deals with the method of self-equilibrium stress mode analysis of cable dome structures. From the point of view of analysis, cable dome structure is a kind of unstable truss structure which is stabilized by means of introduction of prestressing. The prestress must be introduced according to a specific proportion among different structural member and it is determined by an analysis called self-equilibrium stress mode analysis. The mathematical equation involved in the self-equilibrium stress mode analysis is a system of linear equations which can be solved numerically by adopting the concept of Moore-Penrose generalized inverse. The calculation of the generalized inverse is carried out by rank factorization method. This method involves a parameter called epsilon which plays a critical role in self-equilibrium stress mode analysis. It is thus of interest to investigate the range of epsilon which produces consistent solution during the analysis of self-equilibrium stress mode.

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Equilibrium Stress Mode Determination of Tensegrity Structure by CAD (CAD를 이용한 텐세그리티 구조물의 평형응력모드 결정법)

  • Kim, Jae-Yeol
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.2
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    • pp.81-88
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    • 2012
  • Cable dome structures are composed of cables-masts and the cables should be in pre-tension since a structure without pre-tension is not stable. Under the pretension, self equilibrium stress state is the main characteristic of a cable dome structure. In this paper, a new method based on the basic principle of closed force polygon for equilibrium system is proposed for the determination of self-equilibrium mode of cable dome structure. The proposed method which is called geometric method has the unique characteristic of visualization of the force mode needed for maintenance of self-equilibrium. The basic theory for a self equilibrium of structure is that the summation of forces at each joint without any external load should be zero. The simplicity of the method which involves only drawing close polygon with the aid of suitable CAD software has been illustrated by means of a example. The results compared with mechanical calculation and existed method and shows good agreement.

Form-Finding of Tensegrity Structures based on Eigenvalue Formulation (고유치문제로 정식화된 텐세그러티 구조물의 형상탐색)

  • Jung, Mi-Roo;Lee, Jae-Hong
    • Journal of Korean Association for Spatial Structures
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    • v.10 no.2
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    • pp.87-94
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    • 2010
  • Form-Finding of tensegrity structures by eigenvalue problem is presented, In ardor to maintain the structures stable, "Form-Finding" should be performed. The types of analytical methods are known to solve this phenomenon: One is to use force density method, and the other is to apply so called, generalized inverse method. In this paper, new form finding methods are presented to obtain the self-equilibrium stress of the tensegrity structures. This method is based on the equilibrium equation of the all of the joint and the governing equation is formulated as eigonvalue problem. In order to verify this approach, numerical example(tensegrity structures) are compared with others calculated by previous methods. The solution by present method is shown identical results. Furthermore, the developed process to find the results is more efficient than previous approaches.

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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.