• 국제강구조저널
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• 제18권5호
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• pp.1525-1540
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• 2018

A test rig with multi-functional purposes was specifically designed and manufactured to study the behavior of multi-planar welded tubular joints subjected to multi-planar concurrent axial loading. An experimental investigation was conducted on full-scale welded tubular joints with each consisting of one chord and eight braces under monotonic loading conditions. Two pairs or four representative specimens (two specimens for each joint type) were tested, in which each pair was reinforced with two kinds of different internal stiffeners at the intersections between the chords using welded rectangular hollow steel sections (RHSSs) and the braces using rolled circular hollow steel sections (CHSSs) and welded RHSSs. The effects of different internal stiffeners at the chord-brace intersection on the load capacity of joints under concurrent multi-planar axial compression/tension are discussed. The test results of joint strengths, failure modes, and load-stress curves are presented. Finite element analyses were performed to verify the experimental results. The study results show that the two different joint types with the internal stiffeners at the chord-brace intersection under axial compression/tension significantly increase the corresponding ultimate strength to far exceed the usual design strength. The load carrying capacity of welded tubular joints decreases with a higher degree of the manufacturing imperfection in individual braces at the tubular joints. Furthermore, the interaction effect of the concurrent axial loading applied at the welded tubular joint on member stress is apparent.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.511-516
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• 2008

Recently, many researchers are studying a high-strength concrete, composite materials and composite structures to build structures more economic and stable all over the world. For instance, there is CFTA(Concrete Filled and Tied Steel Tubular Arch) girder that applies an arch structure and a pre-stressed structure to CFT(Concrete Filled Steel Tubular) Structure to maximize the efficiency of structure and economic. In this study, linear-elastic behavior analysis of CFTA gider filled with high-strength concrete was performed by using ABAQUS 6.5-1 and also the result was analyzed.

• 복합신소재구조학회 논문집
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• 제4권3호
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• pp.13-21
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• 2013

In this study, uniaxial compression tests were performed to investigates the stress-strain relations of Double Skinned Composite Tubular Columns reinforced with steel tube. The confined concrete has been known as the strength of concrete increases significantly. Specimens reinforced with outer and inner steel tube were tested by uniaxial compression test. To investigate the influence of concrete strength increase by confining conditions in steel tubes, 8 specimens with different thickness of tube, hollowness ratio and concrete strength were tested and compared with other researcher's concrete material model.

• 한국공간구조학회논문집
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• 제2권2호
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• pp.51-58
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• 2002

This paper is presented an experimental studies on bond stress between steel and concrete in concrete filled 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.

• 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.

• 한국구조물진단유지관리공학회 논문집
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• 제6권4호
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• pp.119-127
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• 2002

본 연구의 목적은 강관구조물에서 고력볼트로 인장접합되는 플랜지 이음의 거동을 연구하는데 목적이 있다. 9개의 플랜지 이음 실험체의 실험을 수행하였으며, 실험시 고력볼트의 변형율과 이음부의 변형율 그리고 변위를 측정하였다. 고력볼트의 변형율, 플랜지 사이에서 발생하는 지레반력 그리고 강관과 플랜지 판의 응력분포를 연구하였다. 원형강관 플랜지 이음 설계에 사용되는 기준식을 비교 분석하였다.

• Steel and Composite Structures
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• 제51권6호
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• pp.619-645
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• 2024

In the construction industry, composite structures have revolutionized traditional design principles, opening innovative possibilities. The Concrete Encased - Concrete Filled Steel Tubular (CE-CFST) column stands out as a distinctive composite structure, offering structural stability and resilience for various engineering applications. Comprising Reinforced Concrete (RC) and Concrete Filled Steel Tubular (CFST) components, CE-CFST columns are valued for their inherent properties, including ductility and rigidity, CE-CFST is commonly used in the construction of bridges, high-rise buildings, and more. This article aims to provide a concise overview of the evolutionary development of CE-CFST columns and their performance in structural applications. Through a comprehensive review, the study delves into the behaviour of CE-CFST columns under different scenarios. It examines the influences of key parameters such as size, infills, cross section, failure causes, and design codes on the performance of CE-CFST columns, highlighting their enhanced functionality and future potential. Moreover, the review meticulously examines previous applications of CE-CFST columns, offering insights into their practical implementation.

• 한국의류학회지
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• 제35권8호
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• pp.968-981
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• 2011

This study examines the effect of the structure of Intarsia and Jacquard knit on mechanical properties of knit fabrics to suggest data for knit design. Intarsia and 7 types of Color Jacquard (Floating Jacquard, Normal Jacquard, Bird's eye Jacquard, Tubular Jacquard, Ladder's back Jacquard, Blister Jacquard, and Transfer Jacquard) were used. The samples with a gauge of 14 were knitted using 100% wool 2/48's yarn by Shima Seiki SIG computer knitting machine. The Objective Hand was measured by KES-FB system and HV and THV were calculated by the formula of KN-402-KT and KN-301-winter respectively. The results showed that Intarsia and Floating Jacquard are thin, flexible and light, Bird's eye Jacquard is slick, flat and slim, Tubular Jacquard is stiff and undrapable, Ladder's back Jacquard is difficult in shearing deformation and relatively bulky, Blister Jacquard is thickest and transfer jacquard is uneven in surface contour. The selection of proper structure is important for the knit apparel production since the thickness and weight of knit determine the amount of yarn needed and consequently the production cost. The hands of Ladder's back Jacquard and Tubular Jacquard are superior to those of other structures. Intarsia and Floating Jacquard which are thin, light and flexible seem to be good structures for designs showing a body silhouette whereas, Bird's eye Jacquard, Tubular Jacquard and Blister Jacquard (which are thick, heavy, and stiff) are suitable for a boxy silhouette.

• 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.

• Wind and Structures
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• 제30권1호
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• pp.29-35
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• 2020

This paper presents a comparative structural analysis of lattice hybrid tower with six legs with conventional tubular steel tower for an onshore wind turbine using finite element method. Usually a lattice hybrid tower will have a conventional industry standard 'L' profile section for the lattice construction with four legs. In this work, the researcher attempted to identify and analyze the strength of six legged lattice hybrid tower designed with a special profile instead of four legged L profile. And to compare the structural benefits of special star profile with the conventional tubular tower. Using Ansys, a commercial FEM software, both static and dynamic structural analyses were performed. A simplified finite element model that represents the wind turbine tower was created using Shell elements. An ultimate load condition was applied to check the stress level of the tower in the static analysis. For the dynamic analysis, the frequency extraction was performed in order to obtain the natural frequencies of the tower.