• Title/Summary/Keyword: Dome structures

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Analysis of key elements of single-layer dome structures against progressive collapse

  • Zhang, Qian;Huang, Wenxing;Xu, Yixiang;Cai, Jianguo;Wang, Fang;Feng, Jian
    • Steel and Composite Structures
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    • v.42 no.2
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    • pp.257-264
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    • 2022
  • The analysis of the progressive collapse resistance of structures is a well-known issue among structural engineers. Large-span reticulated dome structures are commonly utilized in large public buildings, necessitating research into their progressive collapse resistance to assure user safety. The most significant part of improving the structural resilience of reticulated domes is to evaluate their key elements. Based on a stiffness-based evaluation approach, this work offers a calculating procedure for element importance coefficient. For both original and damaged structures, evaluations are carried out using the global stiffness matrix and the determinant. The Kiewitt, Schwedler, and Sunflower reticulated domes are investigated to explore the distribution characteristic of element importance coefficients in the single-layer dome structures. Moreover, the influences of the load levels, load distributions, geometric parameters and topological features are also discussed. The results can be regarded as the initial concept design reference for single-layer reticulated domes.

A Study on the Static Instability Behaviour of the Zetlin Type Cable Dome Structures (Zetlin형 케이블 돔 구조물의 정적 불안정 거동에 관한 연구)

  • 김형석;김승덕;강문명
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.541-548
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    • 2002
  • Membrane, cable structure and membrane-cable structural system are more lighter than another common structural system, and these are able to be effectively build Lip spatial structures using axial stiffness. However when the load reach at critical load level, it might be happened snap-through or bifurcation according to the structure's shape, and these collapse mechanism should be very important in the design of structures. So, In this paper we study static instability of Zetlin-type cable dome, one of the hybrid cable dome. Moreover, as the unstable behavior of shell structures are very sensitive to the initial condition, we seek to find the effect of initial condition.

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A Study on Natural Vibration Characteristics of Dome Structure According to Natural Frequency Ratio of Substructure (하부 구조의 고유 진동수비에 따른 돔 구조의 고유 진동 특성에 관한 연구)

  • Park, Kwang-Seob;Kim, Yun-Tae
    • Journal of Korean Association for Spatial Structures
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    • v.18 no.3
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    • pp.75-82
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    • 2018
  • Large space structures exhibit different natural vibration characteristics depending on the aspect ratio of structures such as half-open angle. In addition, since the actual large space structure is mostly supported by the lower structure, it is expected that the natural vibration characteristics of the upper structure and the entire structure will vary depending on the lower structure. Therefore, in this study, the natural vibration characteristics of the dome structure are analyzed according to the natural frequency ratio by controlling the stiffness of the substructure. As the natural frequency of the substructure increases, the natural frequency of the whole structure increases similarly to the natural frequency of the upper structure. Vertical vibration modes dominate at $30^{\circ}$ and $45^{\circ}$, and horizontal vibration modes dominate at $60^{\circ}$ and $90^{\circ}$.

RESEARCH ON LOAD-BEARING PROPERTY AND DESIGN OF CABLE DOMES

  • Shen Cao;Zi Zhu
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.596-605
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    • 2005
  • The cable dome, proposed by Geiger after developing Fuller's idea of tensegrity and improved by Levy, is a new type of large span space structures. In this paper, formulations of the initial forces distribution in members of two main systems of cable dome, which are Geiger dome and Levy dome, are presented. By analyzing the static performance of Levy dome and the variation of internal forces in members of the structure, four groups of design parameters in cable dome structure are represented in terms of: (1) the numbers of rings and the spaces between the rings; (2) the slopes of ridge cables; (3) the lengths of struts; (4) the initial force in one member of the structure.

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An Advanced Design Procedure for Dome and Ring Beam of Concrete Containment Structures (콘크리트 격납구조물 돔과 링빔의 개선된 설계기법)

  • Jeon, Se-Jin;Kim, Young-Jin
    • Journal of the Korea Concrete Institute
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    • v.22 no.6
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    • pp.817-824
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    • 2010
  • The concrete containment structures have been widely used in nuclear power plants, LNG storage tanks, etc., due to their high safety and economic efficiency. The containment structure consists of a bottom slab, wall, ring beam and dome. The shape of the roof dome has a very significant effect on structural safety, the quantity of materials, and constructability; the thickness and curvature of the dome should therefore be determined to give the optimum design. The ring beam plays the role as supports for the dome, resulting in a minimized deformation of the wall. The main issues in designing the ring beam are the correct dimensions of the section and the prestress level. In this study, an efficient design procedure is proposed that can be used to determine an optimal shape and prestress level of the dome and ring beam. In the preliminary design stage of the procedure, the membrane theory of shells of revolution is adopted to determine several plausible alternatives which can be obtained even by hand calculation. Based on the proposed procedures, domes and ring beams of the existing domestic containment structures are analyzed and some improvements are discussed.

A Study on the Shape Modeling and Structural Stability of an Icosahedron-typed Modular Dome (정20면체 모듈러 돔의 형상모델링 및 구조안정성에 관한 연구)

  • Shon, Su-Deok;Woo, Hyo-Jun;Lee, Seung-Jae
    • Journal of Korean Association for Spatial Structures
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    • v.15 no.2
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    • pp.51-59
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    • 2015
  • In this study, a shape design and an analysis considering structural stability were investigated to develop an icosahedron-based hemispherical modular dome. To design this modular dome, a program that can perform icosahedron shape modeling, modularization of joint connection members, and the analysis of structural stability was developed. Furthermore, based on the adopted numerical model, the eigen buckling mode, unstable behavior characteristics according to load vector, and the critical buckling load of the modular dome under uniformly distributed load and concentrated load were analyzed, and the resistance capacities of the structure according to different load vectors were compared. The analysis results for the modular dome suggest that the developed program can perform joint modeling for shape design as well as modular member design, and adequately expressed the nonlinear behaviors of structured according to load conditions. The critical buckling load results also correctly reflected the characteristics of the load conditions. The uniformly distributed load was more advantageous to the structural stability than concentrated load.

Buckling Analysis of Rectangular Lattice Dome According to Rise-Ratio -Evaluate Rigidity of Roof Material By Effective Width of Frame (라이즈비에 따른 사각형 격자 돔의 좌굴해석 -지붕재의 강성을 프레임의 유효폭으로 평가)

  • Park, Sang-Hoon;Suk, Chang-Mok;Jung, Hwan-Mok;Kwon, Young-Hwan
    • Journal of Korean Association for Spatial Structures
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    • v.3 no.2 s.8
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    • pp.69-75
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    • 2003
  • In case of rectangular lattice dome 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 one with roof material. In a case like this, shearing rigidity of roof material increases buckling-strength of the whole of structure and can be designed economically from the viewpoint of practice. In case of analysis is achieved considering roof material that adheres to lattice of dame, there is method that considers the rigidity that use effective width frame as method to evaluate rigidity of roof material. therefore, this study is aimed at deciding effective width of roof material united with rectangular lattice dome to evaluate rigidity of roof material by effective width of frame and investigating how much does rigidity of roof material united with lattice of dome increase buckling-strength of the whole of structure according to rise-ratio. Conditions of loading are vertical-type-uniform loading. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems.

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Appraisal of deployable dome structures under wind loading

  • Parke, G.A.R.;Toy, N.;Savory, E.;Abedi, K.;Chenaghlou, R.
    • Wind and Structures
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    • v.1 no.4
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    • pp.317-336
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    • 1998
  • In this paper the appraisal of a folding dome structure under the influence of wind loading is discussed. The foldable structure considered is constructed from an assembly of interconnected elements, together with a flexible membrane, all of which are initially store in a compact form and on deployment expand, like an umbrella, into a dome structure. Loading on the dome was obtained from a wind tunnel analysis of the pressure distribution over the roof of a 1:10 scale model of the structure. The critical loading obtained from the wind tunnel investigation was used, together with individual member and material tests, to form a series of numerical non-linear finite element models which were, in turn, used to investigate the forces within the structure. The numerical analysis was used to determine the critical wind loading that the structure can sustain, as well as providing a method by which to investigate the failure modes of the structure. In order to enhance the load carrying capacity of the dome it was found that both the strength and stiffness of the structural nodes needed to be enhanced and in addition, changes were necessary to substantially increase the stiffness of the individual member and caps.

Fluctuating Pressure Coefficients Distributions for Elliptical Dome Roof (타원형 돔 지붕의 변동풍압특성)

  • Lee, Jong-Ho;Cheon, Dong-Jin;Kim, Yong-Chul;Park, Sang-Woo;Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.4
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    • pp.63-71
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    • 2020
  • The fluctuating wind pressure of the low rise ratio(f/D=0.1) for the elliptical dome roof was analyzed to compare it with the previous studies of circular dome roofs. Wind tunnel test were conducted on a total of 10 wind directions from 0° to 90° while changing wall height-span ratios(H/D=0.1-0.5). For this, meanCP, rmsCP and wind pressure spectrum were analyzed. The analysis result leads to find differences in the shape of the spectra in the spanwise direction and leeward of the elliptical dome according to the wind direction variations of the elliptical dome roof.

A Study on the Stability of the Single-Layer Latticed Dome during Erection Using the Step-Up Method (Step-Up 공법에 의한 단층래티스돔의 시공시 안정성 연구)

  • Koo, Choong-Mo;Jung, Hwan-Mok;Kim, Cheol-Hwan
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.4
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    • pp.109-118
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    • 2012
  • The large-space single-layer lattice dome is relatively simpler in terms of the arrangement of the various framework members and of the design of the junction than the multi-layered lattice dome, can reduce the numbers and quantity of the framework members, and has the merit of exposing the beauty of the framework as it stands. The single-layer lattice dome, however, requires a stability investigation of the whole structure itself, along with an analysis of the stress of the framework members, because an unstable phenomenon called "buckling" occurs when its weight reaches critical levels. Many researchers have systematically conducted researches on the stability evaluation of the single-layer lattice dome. No construction case of a single-layer lattice dome with a 300-m-long span, however, has yet been reported anywhere in the world. The large-space dome structure is difficult to erect due to the gigantic span and higher ceiling compared with other common buildings, and its construction cost is generally huge. The method of erecting a structure causes major differences in the construction cost and period. Therefore, many researchers have been conducting various researches on the method of erecting such structure. The step-up method developed by these authors can reduce the construction cost and period to a great extent compared with the other general methods, but the application of this method inevitably requires the development of system supports in the center section as well as pre-existing supports in the boundary sections. In this research, the safety during the construction of a single-layer lattice dome with 300-m-long span using pre-existing materials was examined in the aspect of structural strength, and the basic data required for manufacturing the supports in the application of the step-up method developed by these authors during the erection of the roof structure were obtained.