• 제목/요약/키워드: space truss

검색결과 186건 처리시간 0.023초

포스트텐션에 의해 시공된 공간 트러스의 거동 (Behaviour of Space Truss Erected by Post-tensioning)

  • 김진우
    • 한국해양공학회:학술대회논문집
    • /
    • 한국해양공학회 2000년도 추계학술대회 논문집
    • /
    • pp.204-209
    • /
    • 2000
  • This paper suggests that post-tensioned and dome-shaped space truss formed by post-tersionong is easy to fabricate in construction process. In particular, a laboratory model is used to show how a flat space truss system can be transformed into a dome-shaped space truss by means of post-tensioning. There are some diserpancy in vertical displacement of the dxperiment and theoretical analysis for space truss. Nonlinear analysis is used to predict the final shape shape of the space truss, the experiments tndicates that this construction method can offer economy over traditional methods. In addition, the analysis indicates that when all the sxisting mechanisms are controlled, the nonlinear finite element method is more reliable way to predict the shape of the dome-shaped space truss than the linear analysis.

  • PDF

Configurations of double-layer space trusses

  • El-Sheikh, Ahmed
    • Structural Engineering and Mechanics
    • /
    • 제6권5호
    • /
    • pp.543-554
    • /
    • 1998
  • Space truss structures may be fabricated in any of several common grid configurations. With different configurations, the truss performance varies considerably affecting both its competitiveness and suitability for specific applications. The work presented in this paper is an assessment of the most commonly adopted truss configurations and their effect on truss characteristics such as the stiffness/weight value, member stress distribution, number of joints and members, degree of redundancy and cost. The study is parametric and covers wide variations of truss aspect ratios, boundary conditions and span/depth ratios. The results of this study could be of significant value to the design of space truss structures.

Design of space truss structures

  • El-Sheikh, Ahmed
    • Structural Engineering and Mechanics
    • /
    • 제6권2호
    • /
    • pp.185-200
    • /
    • 1998
  • Space truss design usually involves two main assumptions: that truss members are pin-ended, and compression members possess brittle post-buckling characteristics. The validity of these assumptions in the design of a new group of space trusses with continuous chords and eccentric joints is questionable. With chord member continuity and the consequent improvement in compression member behaviour, current design practice might be too conservative. In this paper, it is shown that substantial improvements in overall truss strength have resulted when the true member end conditions are considered, thus indicating potential savings in truss weight with considerable magnitudes.

Optimum design of steel space truss towers under seismic effect using Jaya algorithm

  • Artar, Musa;Daloglu, Ayse T.
    • Structural Engineering and Mechanics
    • /
    • 제71권1호
    • /
    • pp.1-12
    • /
    • 2019
  • This study investigates optimum designs of steel space truss towers under seismic loading by using Jaya optimization algorithm. Turkish Earthquake Code (2007) specifications are applied on optimum designs of steel space truss towers under the seismic loading for different local site classes depending on different soil groups. The proposed novel algorithm does not have any algorithm-specific control parameters and depends only a simple revision equation. Therefore, it provides a practical solution for structural optimization problems. Optimum solutions of the different steel truss examples are carried out by selecting suitable W sections taken from American Institute of Steel Construction (AISC). In order to obtain optimum solutions, a computer program is coded in MATLAB in corporated with SAP2000-OAPI (Open Application Programming Interface). The stress and displacement constraints are applied on the design problems according to AISC-ASD (Allowable Stress Design) specifications. Firstly, a benchmark truss problem is examined to see the efficiency of Jaya optimization algorithm. Then, two different multi-element truss towers previously solved with other methods without seismic loading in literature are designed by the proposed algorithm. The first space tower is a 582-member space truss with the height of 80 m and the second space tower is a 942-member space truss of about 95 m height. The minimum optimum designs obtained with this novel algorithm for the case without seismic loading are lighter than the ones previously attained in the literature studies. The results obtained in the study show that Jaya algorithm is a practical and robust optimization method for structural optimization problems. Moreover, incorporation of the seismic loading causes significant increase in the minimum design weight.

Analytical testing and evaluation of truss typed structures for tunnel maintenance

  • Lee, Dongkyu;Kim, Dohwan;Lee, Jaehong;Noh, Pilsung;Park, Sungsoo
    • Smart Structures and Systems
    • /
    • 제15권4호
    • /
    • pp.949-961
    • /
    • 2015
  • The goal of this study is to present numerical modeling and analytical testing in order to evaluate an innovative space truss typed temporary structure, which is used to maintenance and repair of road tunnels. The present space truss structure has merits to use UL-700 high strength steel tube as members and to carry out maintenance and repair works of road tunnels without blocking cars and transportations. Numerical modeling and analytical testing of the space truss are investigated by using commercial engineering software, i.e., ABAQUS 6.5-1, and then it is verified that the truss structure has both structural safety and effective function for maintenances and repairs of road tunnels.

평면트러스로 지지된 리프트 게이트의 진동특성 (Dynamic Characteristic of Lift Gate Supported by Plane Truss)

  • 이성행;양동운;함형길;공보성;신동욱
    • 한국농공학회논문집
    • /
    • 제54권3호
    • /
    • pp.133-139
    • /
    • 2012
  • Dynamic characteristic of lift gate supported by plane truss is studied by a model test scaled with the ratio of 1 : 31.25 in the four major rivers project. The vibrations of gate supported by the plane truss is assessed in comparison with those of gate supported by the space truss which was tested formerly. The gate model is made of acryl panel and calibrated by lead. A model test is conducted under the different gate opening and upstream water levels conditions in the concrete test flume dimensioned 1.6 m in width, 0.8 m in height and 24 m in length. In order to verify the model, natural frequencies of the model gate are measured, and compared with the numerical results. The vibrations of gate model supported by the plane truss in opening height of 1.0 cm~2.0 cm shows greater than one supported by the space truss. It is found that the gate model supported by the plane truss is less desirable than one supported by the space truss. thus, the latter type of gate model is requested to design.

Effect of direct member loading on space truss behaviour

  • El-Sheikh, Ahmed
    • Structural Engineering and Mechanics
    • /
    • 제10권1호
    • /
    • pp.1-15
    • /
    • 2000
  • It is inevitable that every space truss structure would be under some form of direct member loading. At least the structure self weight certainly affects the members directly, and in structures involving top concrete slabs or cladding, their weight is also likely to apply some lateral pressure on the members. In spite of that, direct member loading is usually ignored in space truss designs and assumed to lead only to a negligible effect on truss performance. This study is intended to explore this point and identify the actual effects that can arise from direct member loading, and eventually provide an answer to the question of whether the current design practice is satisfactory or certain modifications would be needed. After presenting two analytical techniques to allow the study of space trusses with laterally loaded members, the paper describes a wide parametric study involving practical-size space trusses with different configurations, aspect ratios, boundary conditions and number of chord panels.

Influence of Removed Web Members in Shaping Formation for Hypar Space Truss

  • 김진우
    • 한국해양공학회지
    • /
    • 제20권2호
    • /
    • pp.16-21
    • /
    • 2006
  • This paper discusses the behavior of post-tensioned and shaped hypar space truss, with consideration of the influence of removing some web members. Hypar space truss is post-tensioned at the bottom chords of one diagonal on the ground; the essential behavior characteristic of shape formation is discussed by using a small-scale test model. Results of experiments and nonlinear finite-element analysis indicate that a planar, rectangular- arranged structure can be deformed to a predicted hyper shape, by the proposed shape formation method. Also the feasibility of the proposed method for furnishing of a hypar shaped face truss has been presented, under the condition of both non-removed and partially removed web members. It follows that a nonlinear finite element analysis method can be used in predicting the behavior of the space shape and the post-tensioning force in sharing of hypar space truss. Further, in comparison to the other cases, the results of test and analysis show that the active diagonal shaping in the non-removed web members and passive diagonal shaping of partially removed web members are in relatively good agreement.

터널의 유지보수공사 개선을 위한 가설 스페이스 트러스 프레임의 사용성 및 안정성 평가 (Structural and Functional Measurements of a Space Truss Frame for Maintenance Works in Tunnels)

  • 이동규;김도환;김진호
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제16권3호
    • /
    • pp.92-98
    • /
    • 2012
  • 본 연구는 터널의 유지, 보수, 보강에 필요한 가설공사용 스페이스 트러스 프레임 구조물을 소개한다. 기존 가설공사 시공방식과 장비들의 현황 및 문제점을 분석하고, 터널 설계의 핵심 구성요소를 파악함으로써, 제안된 새로운 가설 시공기술 시스템을 개발하는 과정을 순차적으로 설명한다. 그리고 개발된 가설 시스템을 발주처, 시공사, 터널 이용자 관점에서 사용성 및 경제성을 분석하고, 구조적인 안전성 검토와 최적단면 산정 평가를 상용 유한요소 해석프로그램인 ABAQUS 6.5로 구현하여 본 가설 시스템의 현장적용 기반을 구축한다.

기하학적 비선형과 재료적 비선형을 고려한 입체트러스 해석에 관한 연구 (A Study on Non-Linear Matrial and Geomertric Anolysis of Space Truss)

  • 이재문;권영환;김화중
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 1990년도 봄 학술발표회 논문집
    • /
    • pp.1-5
    • /
    • 1990
  • The object of this study introducts simple formula being based on energy principle to investigate span truss's non-linear, and considers the relation of member's length, height rate and slenderness ratio to rise prymid truss's economic structure ability through each example. This paper considered space truss's geometric non-linear behavior and material non-linear behavior, so acquired under result through as saying energy principle.

  • PDF