• Title/Summary/Keyword: spatial latticed structures

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Nonlinear analysis of cable-stayed spatial latticed structures

  • Zhou, Dai;Liu, Hongyu;Jin, Bo
    • Structural Engineering and Mechanics
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    • v.15 no.4
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    • pp.415-436
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    • 2003
  • The combination of spatial latticed structures (hereafter SLS) and flexible cables, the cable-stayed spatial latticed structures (hereafter CSLS) can cross longer span. According to variation principle, a novel geometric nonlinear formulation for 3-D bar elements considering large displacement and infinitesimal rotation increments with second-order precision is developed. The cable nonlinearity is investigated and it is taken that the secant modulus method can be considered as an exact method for a cable member. The tower column with which the cables link is regarded as a special kind of beam element, and, a new simplified stiffness formulation is presented. The computational strategies for the nonlinear dynamic response of structures are given, and the ultimate load carrying capacities and seismic responses are analyzed numerically. It is noted that, compared with corresponding spatial latticed shells, the cable-stayed spatial latticed shells have more strength and more stiffness, and that the verical seismic responses of both CSLS and CLS are remarkably greater than the horizontal ones. In addition, the computation shows that the stiffness of tower column influences the performance of CSLS to a certain extent and the improvement of structural strength and stiffness of CSLS is relevant not only to cables but also to tower columns.

A Study on the Buckling Characteristics of Double-Layer Latticed Domes whose Boundary Configuration are Elliptical (경계부 형상이 타원형인 복층 래티스 돔의 좌굴 특성에 관한 연구)

  • Seo, Young-Ill;Kwun, Ik-No;Kwun, Taek-Jin
    • Journal of Korean Association for Spatial Structures
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    • v.2 no.3 s.5
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    • pp.71-79
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    • 2002
  • The purpose of this paper is to study the buckling characteristics of elliptical latticed domes under conservative loading conditions. The latticed domes are usually designed in geometrically spherical shape. For this type of latticed domes, many researchers have researched and even the simplified estimation codes for the buckling load level have been available. However, geometrically elliptical latticed domes have been often constructed, and show different buckling characteristics following with geometrical parameters as rise-to-span ratio and so on. Therefore, it is necessary to investigate the general tendency of buckling characteristics of the elliptical latticed domes. In this paper, to find out some buckling characteristics of elliptical latticed domes, height, boundary configuration and gap are used as the shape coefficients. For each model with different parameters, the eigen values and the buckling loads are evaluated.

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Reinforcement Effects of Buckling Member for Single-layer Latticed Dome (단층래티스 돔의 좌굴부재 보강효과에 관한 연구)

  • Jung, Hwan-Mok;Yoon, Seok-Ho;Lee, Dong-Woo
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.4
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    • pp.45-52
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    • 2016
  • The single layer latticed domes have attracted many designers and researchers's attention all of the world, because these structures as spatial structure are of great advantage in not only mechanical rationality but also function, fabrication, construction and economic aspect. But single layer latticed domes are apt to occur the unstable phenomena that are called "buckling" because of the lack of strength of members, instability of structural shape, etc. In the case of latticed dome, there are several types of buckling mode such as overall buckling, local buckling, and member buckling according to the shape of dome, section type of member, the size of member, junction's condition of member and so on. There are many methods to increase the buckling strength of the single layer latticed dome, that is, with the change of geometrical shape of dome, the reinforcement of buckled member, etc. Therefore, the purpose of this study is to verify the reinforcement effect of buckled member when designers reinforce the buckled member to increase the buckling strength of single layer latticed dome with 3-way grid.

An Estimation of Buckling-Strength of Braced Rectangular Latticed Domes (브레이스로 보강된 사각형 래티스돔의 좌굴내력 평가)

  • Hwang, Young-Min;Suk, Chang-Mok;Park, Sang-Hoon
    • Journal of Korean Association for Spatial Structures
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    • v.3 no.4 s.10
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    • pp.69-76
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    • 2003
  • In case of rectangular latticed pattern which shearing rigidity is very small, it has a concern to drop Buckling-strength considerably by external force. So, by means of system to increase buckling-strength, there is a method of construction that lattice of dome is reinforced by braced member. In a case like this, shearing rigidity of braced member increase buckling-strength of the whole of structure and can be designed economically from the viewpoint of practice. Therefore, this paper is aimed at investigating how much does rigidity of braced member united with latticed member bearing principal stress of dome increase buckling-strength of the whole of structure. the subject of study is rectangular latticed domes that are a set of 2-way lattice dome which grid is simple and number of member gathering at junction is small. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems.

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A Study on the Bucking Load Formulae for the Single Layer Latticed Dome (단층 래티스 돔의 좌굴하중 산정식에 관한 연구)

  • Han, Sang-Eul;Yang, Jae-Geun;Lee, Sang-Ju;Lee, Jung-Hyun
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.1 s.19
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    • pp.75-82
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    • 2006
  • The single layer latticed dome is very sensitive on the slenderness ratio and half open angle of the elements, load condition, and the connection type because it is organized by a lot of thin elements, so we have to use the geometrically nonlinear buckling load when the buckling of the structures is analyzed. But, it is very difficult to design the single layer latticed domes considered all renditions. Therefore the purpose of this paper is to propose the appropriate design method of the single layer latticed dome considered the geometrically nonlinear buckling load in base of the linear buckling load by the eigenvalue analysis.

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Buckling Analysis of Spherical Shells With Periodic Stiffness Distribution (주기적인 강성분포를 갖는 구형쉘의 좌굴해석)

  • Jung, Hwan-Mok
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.4 s.14
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    • pp.77-84
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    • 2004
  • Researches on spherical shell which is most usually applied have been completed by many investigators already and generalized numerical formula was derived. But the existent researches are limited to those on spherical shell with isotropic or orthotropic roof stiffness, periodic distribution of roof stiffness that can be caused by spherical and latticed roof system is not considered. Therefore, the object of this study is to develop a structural analysis program to analyze spherical shells that have periodicity of roof stiffness distribution caused by latticed roof of large space structure, grasp buckling characteristics and behavior of structure.

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An Experimental Study on Welded Joints for Single-Layer Latticed Domes (단층 래티스 돔의 용접 접합부에 관한 실험연구)

  • Seo, Sang-Hoon;Choi, June-Ho;Lee, Young-Hak;Kim, Hee-Cheul;Kim, Min-Sook;Lee, Sung-Min
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.161-164
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    • 2008
  • Demands for space structures such as domes have increased in Korea. Generally, typical methods for connections of the space structures have technical limits in the space distances of the single latticed domes between supports. In this paper, improved welded joints for single-layer lattice domes was suggested and compared with the existing connections of the single layer latticed domes through both analytical and experimental studies.

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The Elasto-Plastic Buckling Analysis of Ball-Jointed Single Layer Latticed Domes considering the Characteristics of a Connector (적합부 특성을 고려한 볼 접합 단층 래터스 돔의 탄소성 좌굴해석)

  • Han, Sang-Eul;Kwon, Hyun-Jae;Kim, Jong-Bum
    • Journal of Korean Association for Spatial Structures
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    • v.3 no.2 s.8
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    • pp.91-99
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    • 2003
  • The purpose of this study is to analyze the characteristics of the connector having an influence on the elasto-plastic buckling load of ball-jointed single layer latticed domes. As an analytic model, domes are composed of tubular member elements, balls and connectors. The joint system of members in single layer latticed domes has influence on the buckling load. Therefore, in this paper, the variation of the elasto-plastic buckling load by effects of the connectors characteristics is analyzed. The structural behavior of the connector is investigated by following points: (1) the length of rigid zone, (2) looseness of screw and (3) the diameter of connector. In addition, the elasto-plastic buckling analysis is carried out through the variation of the connectors section of yielding part, and then the buckling mode of the dome is examined. As a result, it is emphasized that the characteristics of the connector have significant effects on the buckling load of latticed domes.

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