• 한국산업융합학회 논문집
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• 제22권6호
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• pp.615-626
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• 2019

In this study, the applicability of PHC pile jointing method using rectangular steel tubular was studied. PHC pile joints are welded and bolt assembly. The bolt assembly method is a method that improves the various problems of welded joints. Numerical analysis and tests were conducted to analyze the applicability of the PHC pile jointing method using a rectangular steel tubular. The tests were carried out to test the material properties of the rectangular steel tubular material and the bending test of the pile joints. The numerical analysis was interpreted in the same conditons as the tests conditions. As a result, the material strength of each rectangular steel tubular could be used as a joint material. In the bending test, it was evaluated as a sTable material above the allowable stress of piles. In the numerical analysis results under the same conditions as the tests, it was possible to apply the pile joint material without exceeding the allowable stress of the material.

• Steel and Composite Structures
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• 제18권1호
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• pp.71-90
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• 2015

Axial compression tests have been carried out on 18 rectangular concrete-filled cold-formed steel tubular (CFST) columns with the aim of investigating the axial behaviour of rectangular CFST columns under different loading methods (steel loaded-first and full-section loaded methods). The influence of different loading methods on the ultimate strength of the specimens was compared and the development of Poisson's Ratio as it responds to an increasing load was reported and analysed. Then, the relationship between the constraining factor and the strength index, and the relationship between the constraining factor and ductility index of the specimens, were both discussed. Furthermore, the test results of the full-section loaded specimens were compared with five international code predicted values, and an equation was derived to predict the axial carrying capacity for rectangular CFST columns with a steel loaded-first loading method.

• 한국공간구조학회논문집
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• 제3권3호
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• pp.105-110
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• 2003

This paper is presented an experimental studies on bond stress between steel and concrete in concrete filled Rectangular steel tubes. In the actual building frames, vertical dead and live loads on beams are usually transferred to columns by beam-to-column connections. In case when concrete filled steel tubes are used as columns of an actual building frame which has a simple connection, shear forces in the beam ends are not directly transferred to the concrete core but directly to the steel tube. Provided that the bond effect between steel tube and concrete core should not be expected, none of the end shear in the beams would be transferred to the concrete core but only to the steel tube. Therefore, it is important to investigate the bond strength between steel tube and concrete core in the absence of shear connectors.

• Steel and Composite Structures
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• 제22권5호
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• pp.1073-1084
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• 2016

Rectangular concrete-filled steel tubular columns with unequal wall thickness were investigated in the paper. The physical centroid, the centroidal principal axes of inertia, and the section core were given. The generalized bending formula and the generalized eccentric compression formula were deduced, and the equation of the neutral axis was also provided. The two rectangular concrete-filled steel tubular stub specimens subjected to the compression load on the physical centroid and the geometric centroid respectively were tested to verify the theoretical formulas.

• Steel and Composite Structures
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• 제6권1호
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• pp.55-69
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• 2006

The results of tests conducted on 11 concrete-filled steel tubular columns were reported. Concrete was partially filled in circular steel tubular columns. The primary test parameters were radius and thickness of steel tubes, concrete height, loading patterns and attachment of diaphragm and studs. Concrete strain was measured directly by embedding strain gauges so that the effect of diaphragm on concrete confinement could be investigated. The effects of concrete height and diaphragm on ultimate strength and ductility of steel tubes were investigated. The comparisons of the test results with the existing results for rectangular cross-sections were made on the basis of ultimate strength and ductility of concrete-filled steel tubular columns.

• Steel and Composite Structures
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• 제8권2호
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• pp.115-128
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• 2008

A method is proposed to estimate the ultimate strength of rectangular concrete-filled steel tubular (CFT) stub columns under axial compression. The ultimate strength of concrete core is determined by using the conception of the effective lateral confining pressure and a failure criterion of concrete under true triaxial compression, which takes into account the difference between the lateral confining pressure provided by the broad faces of the steel tube and that provided by the narrow faces of the steel tube. The longitudinal steel strength of broad faces and that of the narrow faces of the steel tube are calculated respectively due to that buckling tends to occur earlier and more extensively on the broader faces. Finally, the proposed method is verified with experimental results. Corresponding values of ultimate strength calculated by ACI (2005), AISC (1999) and GJB4142-2000 are given respectively for comparison. It is found from comparison that the proposed method shows a good agreement with the experimental results.

• 한국강구조학회 논문집
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• 제11권1호통권38호
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• pp.89-98
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• 1999

본 연구는 콘크리트충전 각형강관 기둥의 중심 및 편심압축 실험을 통해 비탄성역에서의 좌굴내력을 구하고, 그 결과를 비교 분석하여 기둥의 각 변수에 따른 내력 및 변형능력에 미치는 영향을 종합적으로 파악하며, 각국의 규준식과 비교하여 새로운 내력식을 제안하여 콘크리트충전 각형강관 기둥을 이용한 고층구조시스템의 개발에 필요한 구조역학적 정보를 제공하고, 향후 국내의 콘크리트충전 강관구조 규준 제정에 필요한 기초 자료를 제시하는데 그 목적이 있다.

• 한국해양공학회지
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• 제8권2호
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• pp.141-150
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• 1994

In designing, the strength of tubular joint has been an important problem for integrity of steel structures in which many tubular members are used. This paper presents the results of FEM analysis on stress concentration and fatigue crack initiation life for two types of tubular joints. One is circular and rectangular T type joints which consist of circular brace and rectangular chord. Another is circular and circular T type joints which consist of circular brace and circular chord. FEM analyses were performed under the axial load and in-plane bending moment. The fatigue crack initiation life can be estimated by using $\varepsilon$-N curve and by applying the Palmgren-Miner linear damage rule. According to the results, the stress concentration factor(SCF) of circular and rectangular joints is higher than that of circular and circular joints. The fatigue crack initiation lives of circular-circular joints and circular-rectangular joints were calculated.

• Steel and Composite Structures
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• 제3권3호
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• pp.199-212
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• 2003

An experimental investigation of lightweight aggregate and foamed concrete contribution to the ultimate strength capacity of square and rectangular steel tube sections is presented in this study. Thirty-four simply supported beam specimens, 1000-mm long, filled with lightweight aggregate and foamed concretes were tested in pure flexural bending to calculate the ultimate moment capacity. Normal concrete-filled steel tubular and bare steel sections of identical dimensions were also tested and compared to the filled steel sections. Theoretical values of ultimate moment capacity of the beam specimens were also calculated in this study for comparison purposes. The test results showed that lightweight aggregate and foamed concrete significantly enhance the load carrying capacity of steel tubular sections. Furthermore, it can be concluded from this study that lightweight aggregate and foamed concretes can be used in composite construction to increase the flexural capacity of the steel tubular sections.

• 한국강구조학회 논문집
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• 제16권4호통권71호
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• pp.463-470
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• 2004

본 연구에서는 중심축하중을 받는 각형강관기둥의 베이스플레이트의 지압응력의 분포와 설계에 대하여 조사하였다. 일반적으로 강구조 기둥의 베이스플레이트는 지압응력이 등분포하다고 가정하고 그 크기와 두께를 결정한다. 그러나 축하중이 적으면 베이스플레이트의 크기도 작아지고 두께도 얇아지며 지압응력은 등분포하게 되지 않으며 기둥단면의 하부에 집중된다. 본 연구에서는 실험적 방법과 해석적 방법으로 지압응력의 분포에 대하여 조사하고 그 결과를 이용하여 설계법을 검토하였다. 4개의 각형강관기둥 베이스플레이트 시험체를 제작하여 실험을 수행하였다. 또한 유한요소해석프로그램인 ANSYS를 이용하여 베이스플레이트의 지압응력의 분포를 해석하였다. 연구결과 축하중이 적은 경우 지압응력은 기둥단면의 하부에 집중되고 등분포하지 않으므로 유효폭의 개념을 이용하여 베이스플레이트를 설계하는 방법이 적절함을 나타내었다.