• Steel and Composite Structures
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• 제50권5호
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• pp.499-513
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• 2024

This paper describes the experimental and numerical investigations of octagonal Concrete-Filled Double Skinned Steel Tube (CFDST) short columns under the influence of various internal sizes of the circular and square steel tubes, with constant cross-sectional dimensions of the external octagonal steel tube under concentric loading. The non-linear finite element analysis of octagonal CFDST columns was executed using the ABAQUS to forecast and compare the axial compression behavior influenced by the various sizes of internal circular and square steel tubes. The study shows that the axial compressive strength and ductility of octagonal CFDST columns were significantly influenced by various internal dimensions of the circular and square steel tubes with the strengths of constituent materials.

• 한국강구조학회 논문집
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• 제20권5호
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• pp.655-663
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• 2008

본 연구에서는 콘크리트충전 원형강관(원형 CFT)기둥의 내화성능을 평가하기 위하여 수치해석을 수행하였다. 강관은 SPSR 400 강재를 사용하였으며 강관 내에는 27.5MPa와 37.8MPa 강도의 콘크리트를 사용하였다. 콘크리트 강도, 작용 축력, 단면 직경을 변수로 설정하였다. 수치해석의 정확성을 검증하기 위하여, 기존의 각국 내화성능설계식들에 의한 계산 결과값과 비교 평가 하였다. 또한, 기존의 실대 원형 CFT기둥의 내화성능 평가 실험 결과와 함께 비교 분석하여 수치해석의 타당성을 검증하였다. 원형 CFT기둥의 내화실험 및 수치해석적 연구를 통해 도출된 내화저항시간과 축력비, 단면직경, 콘크리트 강도의 영향을 각형 CFT기둥의 내화성능과 비교 분석하여 각 영향인자들의 영향을 평가하였다. 본 연구의 수치해석적 연구는 실험결과와 비슷한 거동 및 내화성능을 보였다. 따라서 본 연구에서의 수치해석에 의한 CFT기둥의 내화 성능 예측은 타당하다고 판단된다.

• 한국지진공학회논문집
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• 제16권5호
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• pp.23-32
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• 2012

최근 국내에서는 원자력발전소의 모듈화 공법에 적용하기 위하여 SC(steel plate concrete) 구조를 개발하는 연구를 진행하고 있다. 이 연구에서는 전단보강이 없는 비보강 SC 전단벽의 횡방향 내진성능 및 강성특성에 대하여 분석하기 위하여 전단벽 모형 시편을 제작하고, 이를 대상으로 정적가력실험을 수행하였다. 실험 결과를 이용하여, 이 논문에서는 비보강 SC 구조의 횡력에 대한 파괴모드의 유형을 분석하고, 단면강도와 부재의 강성 특성을 검토하였다. 그리고 SC 구조용 설계기준에서 제시하는 단면의 강도 계산식과 실험결과를 비교하였다. 연구결과, 비보강 SC 전단벽의 파괴 형태의 하나는 콘크리트와 강판의 부착 상실로 인한 휨전단파괴라는 사실을 발견하였다. SC 구조 전단벽의 벽체 길이방향 거동은 파괴 시까지 벽체 외측의 강판이 내부 콘크리트를 구속하는 효과를 기대할 수 있으므로 연성능력이 향상되는 것이 확인되었다

• Steel and Composite Structures
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• 제34권1호
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• pp.53-73
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• 2020

A novel all-steel miniature bar-type structural fuse (MBSF) with cold formed bolted connections is developed in this study, which consists of a central energy dissipation core cut from a smooth round bar, an external confining tube and nuts. Three types of cross sections for the central energy dissipation core, i.e., triple-cut, double-cut and single-cut cross sections, were studied. Totally 18 specimens were axially tested under either symmetric or asymmetric cyclic loading histories, where the parameters such as cut cross sectional area ratio, length of the yielding portion and cross sectional type were investigated. Numerical simulation of 2 representative specimens were also conducted. An analytical model to evaluate the bending failure at the elastic portion was proposed, and a design method to avoid this failure mode was also presented. The experimental results show that the proposed MBSFs exhibit satisfactory hysteretic performance under both the two cyclic loading histories. Average strain values of 8% and 4% are found to be respectively suitable for designing the new MBSFs as the ultimate strain under the symmetric and asymmetric cyclic loadings.

• 터널과지하공간
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• 제8권4호
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• pp.261-274
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• 1998

이 연구에는 가축성 강재지보에 대한 실내실험 및 현장실험 결과가 제시된다. 시험지보는 단위중량이 25.8kg/m인 Gloken profile U 빔 3매를 조립하여 제작되었다. 양단이 힌지로 지지되는 반원형 및 아치형 지보에 대한 정역학적인 해석이 실시되었다. 실험된 U빔의 형상계수는 1.35이었고 지보형태에 따른 2차 소성힌지의 위치를 산정하였다. 천장부에서 단일집중하중을 받는 아치형 지보의 내하력을 조사하여 이를 지보 각주 길이의 함수로 나타내었다. U 빔 연결부의 결합토크를 변화시키는 실물크기 지보시험을 수행하여 시험지보의 가축특성을 파악하였으며, 결합토크를 설계하는 방법을 연구하였다. 결합토크가 21kg.m 인 시험지보를 현장에 설치하고 계측한 결과 전형적인 가축현상을 관찰할 수 있었다.

• Wind and Structures
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• 제10권2호
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• pp.121-133
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• 2007

To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are schemed, in which the cable's cross-sectional area is determined by the principle of equivalent axial stiffness. Numerical investigations on the dynamic behavior, aerostatic and aerodynamic stability of the two bridges are conducted by 3D nonlinear analysis, and the effect of different cable materials on the wind resistance is discussed. The results show that as CFRP cables are used in cable-supported bridges, (1) structural natural frequencies are all increased, and particularly great increase of the torsional frequency occurs for suspension bridges; (2) under the static wind action, structural deformation is increased, however its aerostatic stability is basically remained the same as that of the case with steel cables; (3) for suspension bridge, its aerodynamic stability is superior to that of the case with steel cables, but for cable-stayed bridge, it is basically the same as that of the case with steel stay cables. Therefore as far as the wind resistance is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable's cross-sectional area should be determined by the principle of equivalent axial stiffness.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1997년도 가을 학술발표회 논문집
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• pp.181-188
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• 1997

This work proposes possible use of the hyperdocument as a companion for structural steel designers and also as a part of any expert system to be used for the design of steel structures. AISC Specification for Structural Steel Buildings - Allowable Stress Design and Plastic Design, June 1, 1989-has been thoroughly hyperdocumented. Database for the most of AISC standard sections has been built for easier reference to sectional properties and even for search for the relevant sections. Hardy and wxCLIPS from AIAI, The University of Edinburgh were used as development tools. Hardy is integrated with NASA's rule-based and object-oriented language CLIPS 6.0 to enable users to rapidly develop diagram-related applications. Currently this work does not include any sophisticated rule-bases. Rather, this work will form a part of the expert systems for the steel structural design to be developed later. Nevertheless, the hyperdocument of this work will make a good companion for structural steel designers in its own right.

• Steel and Composite Structures
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• 제18권5호
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• pp.1239-1258
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• 2015

This paper presents a master-slave constraint method, which may substitute the conventional transformed-section method, to account for the changes in cross-sectional properties of composite members during construction and to investigate the time-dependent performance of steel-concrete composite bridges. The time-dependent effects caused by creep and shrinkage of concrete are considered by combining the age-adjusted effective modulus method and finite element analysis. An efficient computational tool which runs in AutoCAD environment is developed to simulate the construction process of steel-concrete composite bridges. The major highlight of the developed tool consists in a very convenient and user-friendly interface integrated in AutoCAD environment. The accuracy of the proposed method is verified by comparing its results with those provided by using the transformed-section method. Furthermore, the computational efficiency of the developed tool is demonstrated by applying it to a steel-concrete composite bridge.

• Steel and Composite Structures
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• 제13권3호
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• pp.225-238
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• 2012

Steel structural elements with web-tapered I cross section, are usually made of welded thin plates. Due to the nonrectangular shape of the element, thin web section may be obtained at the maximum cross section height. The buckling strength is directly influenced by lateral restraining, end support and initial imperfections. If no lateral restraints, or when they are not effective enough, the global behaviour of the members is characterized by the lateral torsional mode and interaction with sectional buckling modes may occur. Actual design codes do not provide a practical design approach for this kind of elements. The paper summarizes an experimental study performed by the authors on a relevant number of elements of this type. The purpose of the work was to evaluate the actual behaviour of the web tapered beam-columns when applying different types of lateral restraints and different web thickness.

• Structural Engineering and Mechanics
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• 제10권4호
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• pp.371-392
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• 2000

Application of "advanced analysis" methods suitable for non-linear analysis and design of steel frame structures permits direct and accurate determination of ultimate system strengths, without resort to simplified elastic methods of analysis and semi-empirical specification equations. However, the application of advanced analysis methods has previously been restricted to steel frames comprising only compact sections that are not influenced by the effects of local buckling. A concentrated plasticity method suitable for practical advanced analysis of steel frame structures comprising non-compact sections is presented in this paper. The pseudo plastic zone method implicitly accounts for the effects of gradual cross-sectional yielding, longitudinal spread of plasticity, initial geometric imperfections, residual stresses, and local buckling. The accuracy and precision of the method for the analysis of steel frames comprising non-compact sections is established by comparison with a comprehensive range of analytical benchmark frame solutions. The pseudo plastic zone method is shown to be more accurate and precise than the conventional individual member design methods based on elastic analysis and specification equations.