• Title/Summary/Keyword: membrane prestress

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A Study on the Shape Finding and Patterning Procedures for Membrane Structures (막구조의 초기형상 및 재단도 결정알고리즘에 관한 연구)

  • 한상을;이경수;이상주;유용주
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.298-305
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    • 1998
  • The purpose of this study is to propose the method of determining the initial fabric membrane structures surface and membrane patterning procedures. Tension structure, such as, fabric membrane structures and cable-net, is stabilized by their initial prestress and boundary condition. The process to find initial structural overall shape of tension structures produced by initial prestress called Shape Finding or Shape Analysis. One of the most important factor for the design of membrane structures is to search initial smooth surface, because unlike steel or concrete building elements which resist loads in bending, all tension structure forces are carried within the surface by membrane stress or cable tension. To obtain initial surface of fabric membrane element in large deformation analysis, the membrane element is idealized as cable using a technique with Force-density method. and that result is compared with well-known nonlinear numerical method, such as Newton-raphson method and Dynamic relaxation method. The shape resulting from Force-density method has been dealt with as the initial membrane shape and used patterning procedures.

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Shape Finding and Stress Finding for Pneumatic Membrane Structures by Dynamic Relaxation Method (동적이완법에 의한 공기막구조물의 형태탐색과 응력해석)

  • 문창훈;이경수;배종효;최옥훈;한상을
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.04a
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    • pp.268-275
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    • 1999
  • The purpose of this study is to propose the method of determining the initial pneumatic membrane structures surface and stresses and displacements. Tension structure such as pneumatic membrane structures is stabilized by their initial prestress and air pressure. The process to find initial structural overall shape of tension structures produced by initial prestress called shape finding. One of the most important factor for the design of membrane structures is to search initial smooth surface, because unlike steel or concrete building elements which resist loads in bending, all tension structure forces are carried within the surface by membrane stress. The result for initial surface of pneumatic membrane element and maximum displacement in large deformation in analysis is compared with well-known nonlinear numerical method such as Newton-raphson method and dynamic relaxation method

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Numerical study on tensioned membrane structures under impact load

  • Zhang, Yingying;Zhao, Yushuai;Zhang, Mingyue;Zhou, Yi;Zhang, Qilin
    • Structural Engineering and Mechanics
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    • v.71 no.2
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    • pp.109-118
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    • 2019
  • This paper presents the numerical simulation of membrane structure under impact load. Firstly, the numerical simulation model is validated by comparing with the test in Hao's research. Then, the effects of the shape of the projectile, the membrane prestress and the initial impact speed, are investigated for studying the dynamic response and failure mechanism, based on the membrane displacement, projectile acceleration and kinetic energy. Finally, the results show that the initial speed and the punch shape are related with the loss of kinetic energy of projectiles. Meanwhile, the membrane prestress is an important factor that affects the energy dissipation capacity and the impact resistance of membrane structures.

Cable sag-span ratio effect on the behavior of saddle membrane roofs under wind load

  • Hesham Zieneldin;Mohammed Heweity;Mohammed Abdelnabi;Ehab Hendy
    • Wind and Structures
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    • v.36 no.3
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    • pp.149-160
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    • 2023
  • Lightness and flexibility of membrane roofs make them very sensitive to any external load. One of the most important parameters that controls their behavior, especially under wind load is the sag/span ratio of edge cables. Based on the value of the pretension force in the edge cables and the horizontal projection of the actual area covered by the membrane, an optimized design range of cable sag/span ratios has been determined through carrying on several membrane form-finding analyses. Fully coupled fluid structure dynamic analyses of these membrane roofs are performed under wind load with several conditions using the CFD method. Through investigating the numerical results of these analyses, the behavior of membrane roofs with cables sag/span ratios selected from the previously determined optimized design range has been evaluated.

The application of BEM in the Membrane structures interaction with simplified wind

  • Xu, Wen;Ye, Jihong;Shan, Jian
    • Structural Engineering and Mechanics
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    • v.31 no.3
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    • pp.349-365
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    • 2009
  • Membrane structures are quite sensitive to wind and therefore the fluid-solid interaction can not be neglected in dynamic analysis. A boundary element method (BEM) for 3D simulation of wind-structure interaction in tensile membrane structures is presented in this paper. The flow is treated as incompressible and potential. The flow field is solved with boundary element method codes and structural simulation is performed by finite element method software ANSYS. The nonlinear equations system is solved iteratively, with segregated treatment of the fluid and structure equations. Furthermore this method has been demonstrated to be effective by typical examples. Besides, the influence of several parameters on the wind-structure interaction, such as rise-span ratio, prestress and the wind velocity are investigated according to this method. The results provide experience in wind resistant researches and engineering.

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.

Efficient Design Procedure of Concrete Dome and Ring Beam in Containment Structures (콘크리트 격납구조물 돔 및 링빔의 효율적인 설계 기법)

  • Jeon, Se-Jin;Kim, Young-Jin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.139-140
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    • 2010
  • Combined analysis is required for the concrete dome and ring beam of containment structure due to the interaction in section forces. In this study, an efficient design procedure is proposed that can be used to determine the preliminary sections of the dome and ring beam as well as a proper level of prestress in the ring beam, prior to a detailed design. The procedure applies the membrane theory of the shell of revolution.

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A Development of Intersecting Tensegrity System and Analysis of Structural Features for Forming Space (관입형 텐서그리티 구조시스템의 개발 및 공간구축을 위한 구조특성 분석)

  • Lee, Juna;Miyasato, Naoya;Saitoh, Masao
    • Journal of Korean Association for Spatial Structures
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    • v.14 no.4
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    • pp.55-64
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    • 2014
  • In this study, Intersecting Tensegrity System that is integrated solid compression members with tension members was presented. This system is set up by connecting upper and lower compression members of pyramid shape with exterior tension members. In this system, the solid compression members are intersected each other and connected by a tension member in the center. This system is a variation of Tensegrity system, has a improved feature that the system is able to induce prestresses in all of tension members easily by adjusting the distance of a tension member in the center. The proposed system was studied by modeling, and the structural behavior of the system was investigated by mechanical analysis of the model. Furthermore, the features of the structural behavior variations was investigated when the composition elements(total height, size of surface, intersection length, etc.) are changed variously. It was also showed that the system is able to be used as a temporary space structure system with a membrane roof of inverse conical shape.