• Title/Summary/Keyword: Tubular Connection

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An experimental study of connections between I-beams and concrete filled steel tubular columns

  • De Nardin, Silvana;El Debs, Ana Lucia H.C.
    • Steel and Composite Structures
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    • v.4 no.4
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    • pp.303-315
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    • 2004
  • Frame composed of concrete-filled steel tubular columns and I-shaped steel beam has been researched in order to development reasonable connection details. The present paper describes the results of an experimental program in four different connection details. The connection details considered include through-bolt between I-shaped steel beams and concrete-filled steel tubular columns and two details of welded connections. One of the welded connection details is stiffened by angles welded in the interior of the profile wall at the beam flange level. The specimens were tested in a cruciform loading arrangement with variable monotonic loading on the beams and constant compressive load on the column. For through-bolt details, the contribution of friction and bearing were investigated by embedding some of the bolts in the concrete. The results of the tests show that through-bolt connection details are very ductility and the bearing is not important to the behavior of these moment connections. The angles welded in the interior of the profile wall increase the strength and stiffness of the welded connection detail. In addition, the behavior curves of these connections are compared and some interesting conclusions are drawn. The results are summarized for the strength and stiffness of each connection.

Tubular Web Reduced Beam Section (TW-RBS) connection, a numerical and experimental study and result comparison

  • Zahrai, Seyed M.;Mirghaderi, Seyed R.;Saleh, Aboozar
    • Steel and Composite Structures
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    • v.23 no.5
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    • pp.571-583
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    • 2017
  • A kind of accordion-web RBS connection, "Tubular Web RBS (TW-RBS)" connection is proposed in this research. TW-RBS is made by replacing a part of web with a tube at the desirable location of the beam plastic hinge. This paper presents first a numerical study under cyclic load using ABAQUS finite element software. A test specimen is used for calibration and comparison of numerical results. Obtained results indicated that TW-RBS would reduce contribution of the beam web to the whole moment strength and creates a ductile fuse far from components of the beam-to-column connection. Besides, TW-RBS connection can increase story drift capacity up to 9% in the case of shallow beams which is much more than those stipulated by the current seismic codes. Furthermore, the tubular web like corrugated sheet can improve both the out-of-plane stiffness of the beam longitudinal axis and the flange stability condition due to the smaller width to thickness ratio of the beam flange in the plastic hinge region. Thus, the tubular web in the plastic hinge region improves lateral-torsional buckling stability of the beam as just local buckling of the beam flange at the center of the reduced section was observed during the tests. Also change of direction of strain in arc shape of the tubular web section is smaller than the accordion webs with sharp corners therefore the tubular web provides a better condition in terms of low-cycle fatigue than other accordion web with sharp corners.

Bolted connections to tubular columns at ambient and elevated temperatures - A review

  • Leong, S.H.;Sulong, N.H. Ramli;Jameel, Mohammed
    • Steel and Composite Structures
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    • v.21 no.2
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    • pp.303-321
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    • 2016
  • Tubular column members have been widely adopted in current construction due to its numerous advantages. However, the closed-section profile characteristics of tubular columns severely limit the connection possibilities. Welding type is acceptable but discouraged because of on-site issues. Blind-bolted connection is preferable because of its simplicity, economic benefit, and easy assembly. This paper presents a state-of-the-art review on bolted connections to tubular columns for bare steel tubes, including square and circular sections. Available studies on bolted connections at ambient and elevated temperatures are reviewed, but emphasis is given on the latter. Various methods of determining the connection performance through experimental, analytical, component based, and finite element approaches are examined. Future research areas are also identified.

Experimental study on innovative tubular web RBS connections in steel MRFs with typical shallow beams

  • Saleh, Aboozar;Zahrai, Seyed M.;Mirghaderi, Seyed R.
    • Structural Engineering and Mechanics
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    • v.57 no.5
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    • pp.785-808
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    • 2016
  • An innovative Reduced Beam Section (RBS) connection, called Tubular Web RBS connection (TW-RBS), has been recently introduced and its performance has been numerically investigated in some earlier studies. The TW-RBS connection is a kind of accordion-web RBS connection in which part of the flat web of the beam is replaced by a steel tube at the expected region of the plastic hinge. This paper presents experimental results of three TW-RBS connections under cyclic loading. Obtained results indicated that TW-RBS reduces contribution of the beam web to the whole moment strength and creates a ductile fuse far from components of the beam-to-column connection. Besides, TW-RBS connection can increase story drift capacity up to 9% in the case of shallow beams which is much more than those stipulated by the current seismic codes. Based on the experimental results, the tubular web in the plastic hinge region improves lateral-torsional buckling stability of the beam such that only local buckling of the beam flange at the center of the reduced section was observed during the tests. In order to achieve a better understanding, behavior of all TW-RBS specimens are also numerically investigated and compared with those of experimental results.

Behavior and design of stainless steel tubular member welded end connections

  • Kiymaz, Guven;Seckin, Edip
    • Steel and Composite Structures
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    • v.17 no.3
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    • pp.253-269
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    • 2014
  • Among the various alternatives to make a steel tubular member connection, making a slotted and gusset plate welded connection is one of the most frequently preferred alternatives. This type of connection is essentially an end connection that is made by slotting the tube longitudinally, inserting the gusset plate and then placing longitudinal fillet welds at the tube-to-plate interface. In this paper an experimental study on the behaviour of such connections in stainless steel is presented. 24 specimens were tested under concentrically applied axial tensile forces for varying tube-to-gusset plate weld lengths. Both circular and box section members were considered in the test program. Load-deformation curves were obtained and comparisons were made in terms of strength and ductility. The results obtained from the study were then critically examined and compared with currently available design guidance for slotted gusset plate welded tubular end connections. It is noted that no specific rules exist in international specifications on structural stainless steel which cover the design of such connections. Therefore, the results of this study are compared with the existing design rules for carbon steel.

An experimental study on th reinforced concrete filled tubular column to steel H-beam connections with outer diaphram by simplified connection type (철근콘크리트충전 강관기둥과 외부다이아프램을 보강한 H형강 보 접합부의 단순모형에 의한 실험연구)

  • 김인덕;최병극;박성무
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.587-596
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    • 1997
  • This study is concerning the structural behavior of reinforced concrete filled tubular column to steel H-beam connections with outer diaphram by simplified connection type. The important parameters of this study are the cross-section shape of tubular column and the spacing of hoop (60mm, 30mm, 20mm) and the concrete filled or not. The experimental results are summarized for the strength and displacement of each specimen.

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Test of extended thick-walled through-diaphragm connection to thick-walled CFT column

  • Qin, Ying;Chen, Zhihua;Bai, Jingjing;Li, Zilin
    • Steel and Composite Structures
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    • v.20 no.1
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    • pp.1-20
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    • 2016
  • The strength and stiffness of the steel beams to concrete-filled tubular columns connections are significantly reduced if the thick-walled components are used. However, the thick-walled tubes used for columns can largely reduce the demand for space and increase the strength-to-weight ratio. This paper describes the cyclic performance of extended through-diaphragm connections between steel beams and thick-walled concrete-filled tubular columns improved with fillets around the diaphragm corners. Test on one full-scale connection was conducted to assess the seismic behavior of the connection in terms of strength, stiffness, ductility, deformation, energy dissipation, and strain distribution. It is shown that the fillets and extended through-diaphragm can alleviate the stress concentration in the connection and thus improve the seismic performance. The test results demonstrate that the through-diaphragm connections with thick-walled concrete-filled tubular columns can offer sufficient energy dissipation capacity and ductility appropriate for its potential application in seismic design.

PLASTICITY-BASED WELDING DISTORTION ANALYSIS OF THIN PLATE CONNECTIONS

  • Jung, Gonghyun;Tsai, Chon L.
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.694-699
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    • 2002
  • In autobody assembly, thin-wall, tubular connections have been used for the frame structure. Recent interest in light materials, such as aluminum or magnesium alloys, has been rapidly growing for weight reduction and fuel efficiency. Due to higher thermal expansion coefficient, low stiffness/strength, and low softening temperature of aluminum and magnesium alloys, control of welding-induced distortion in these connections becomes a critical issue. In this study, the material sensitivity to welding distortion was investigated using a T-tubular connection of three types materials; low carbon steel (A500 Gr. A), aluminum alloy (5456-H116) and magnesium alloy (AZ91C-T6). An uncoupled thermal and mechanical finite element analysis scheme using the ABAQUS software program was developed to model and simulate the welding process, welding procedure and material behaviors. The predicted angular distortions were correlated to the cumulative plastic strains. A unique relationship between distortion and plastic strains exists for all three materials studied. The amount of distortion is proportional to the magnitude and distribution of the cumulative plastic strains in the weldment. The magnesium alloy has the highest distortion sensitivity, followed by the other two materials with the steel connection having the least distortion. Results from studies of thin-aluminum plates show that welding distortion can be minimized by reducing the cumulative plastic strains by preventing heat diffusion into the base metal using a strong heat sink placed directly beneath the weld. A rapid cooling method is recommended to reduce welding distortion of magnesium tubular connections.

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Fabrication and Performance Evaluation of Tubular Solid Oxide Fuel Cells Stack (원통형 고체산화물 연료전지 스택 제작 및 성능평가)

  • Kim, Wanje;Lee, Seungbok;Song, Rakhyun;Park, Seokjoo;Lim, Takhyoung;Lee, Jongwon
    • Journal of Hydrogen and New Energy
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    • v.24 no.6
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    • pp.467-471
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    • 2013
  • In present work, optimized the manufacturing process of anode-supported tubular SOFCs cell and stack were studied. For this purpose, we first developed a high performance tubular SOFC cell, and then made electrical connection in series to get high voltage. The gas sealing was established by attaching single cells to alumina jig with ceramic bond. Through these process, we can obtain such high OVP as around 15V, which means that the electrical connection and gas sealing were optimized. Finally we developed a new tubular SOFC stack which shows a maximum power of 65W @ $800^{\circ}C$.