• Steel and Composite Structures
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• v.1 no.3
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• pp.329-340
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• 2001

Cyclic response of "shear" connections between steel outrigger beams and reinforced concrete core walls is presented in this paper. The connections investigated in this paper consisted of a shear tab welded onto a plate that was connected to the core walls through multiple headed studs. The experimental data from six specimens point to a capacity larger than the design value. However, the mode of failure was through pullout of the embedded plate, or fracture of the weld between the studs and plate. Such brittle modes of failure need to be avoided through proper design. A capacity design method based on dissipating the input energy through yielding and fracture of the shear tab was developed. This approach requires a good understanding of the expected capacity of headed studs under combined gravity shear and cyclic axial load (tension and compression). A model was developed and verified against test results from six specimens. A specimen designed based on the proposed design methodology performed very well, and the connection did not fail until shear tab fractured after extensive yielding. The proposed design method is recommended for design of outrigger beam-wall connections.

• Journal of the Korean Society for Advanced Composite Structures
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• v.5 no.4
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• pp.36-43
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• 2014

In this study, circular sectional concrete-filled tube(CFT) column-to-foundation connections were numerically investigated in order to improve their structural details. A inner reinforced specimen with high-tension bolts and inner deformed bars was adopted from a previous experimental study to make the numerical model. The validity of the numerical method was verified through comparing the experimental results with the analysis's ones. In order to optimize design variables about the inner reinforced model, a number of numerical analyses were conducted for various variables. Finally, this study suggested the optimum variables about the reinforced circular sectional CFT column-to-foundation connections.

• Journal of Korean Society of Steel Construction
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• v.28 no.5
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• pp.345-354
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• 2016

In the present study, hybrid moment connections of welding and bar reinforcement for composite beam-column connections were proposed. Concrete-filled octagonal tube and U-section were used for the column and beam, respectively. In the beam-column connection, the top flange and web of the beam U-section were connected to the column plate by welding. However, to reduce stress concentration at the weld joints, the bottom flange of the beam was not welded to the column plate. Instead, to transfer the tension force of the beam flange, reinforcing bars passing through the column plate were used. Four exterior connections with conventional welded and hybrid moment connections were tested under cyclic loading and their cyclic behaviors were investigated. The test results showed that the hybrid moment connections successfully transferred the beam moment to the column. The strength and ductility of the hybrid moment connections were comparable to the conventional welded moment connection with exterior diaphragm; however, the connection performance was significantly affected by the details of the hybrid moment connection.

• 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.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.84-89
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• 2008

Glass fiber reinforced composite decks have high-strength, light-weight and high durability. The composite decks having vertical snap-fit connections are designed for pedestrian bridges and their structural behavior are studied. Especially in this paper, local behavior of the developed composite deck for pedestrian bridge is verified by both analysis and experiment.

• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.1
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• pp.63-71
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• 2014

This study presents an experimental study of the structural behavior for steel plate-concrete column-to-steel girder connections. Experiments were carried out to investigate the moment-rotation characteristics, failure behavior and ultimate moment capacity of these connections. The results of this experimental study involving three welded moment-resisting connections subjected to cyclic loading are presented. The specimens were fabricated at full scale to evaluate their hysteretic behavior. A description of the test specimens, the details of the joint, the test system and the testing methods are described. The test results showed that the structural behavior of these composite connections was influenced by the connection details.

• Steel and Composite Structures
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• v.15 no.5
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• pp.507-518
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• 2013

The seismic performance of six types of weak-axis steel moment connections was investigated through cyclic testing of six full-scale specimens. These weak-axis moment connections were the column-tree type, WUF-B type, FF-W type, WFP type, BFP-B type and DST type weak-axis connections. The testing results showed that each of these weak-axis connection types achieved excellent seismic performance, except the WFP and the WUF-B types. The WFP and WUF-B connections displayed poor seismic performance because a fracture appeared prematurely at the weld joint due to stress concentrations. The column-tree type connection showed the best seismic behavior such that the story drift ratio could reach 5%.

• Steel and Composite Structures
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• v.9 no.6
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• pp.499-518
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• 2009

The present paper investigates the stochastic seismic responses of steel structure systems with Partially Restrained (PR) connections by using Perturbation based Stochastic Finite Element (PSFEM) method. A stiffness matrix formulation of steel systems with PR connections and PSFEM and MCS formulations of structural systems are given. Based on the formulations, a computer program in FORTRAN language has been developed, and stochastic seismic analyses of steel frame and bridge systems have been performed for different types of connections. The connection parameters, material and geometrical properties are assumed to be random variables in the analyses. The Kocaeli earthquake occurred in 1999 is considered as a ground motion. The connection parameters, material and geometrical properties are considered to be random variables. The efficiency and accuracy of the proposed SFEM algorithm are validated by comparison with results of Monte Carlo simulation (MCS) method.

• Steel and Composite Structures
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• v.1 no.4
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• pp.441-458
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• 2001

We analyzed the experimental and theoretical behavior of a particular type of steel joint designed to connect beam to beam and able to transfer both shear forces and bending moments. This joint is characterized by the use of steel plates and bolts enclosed in the width of the beams. The experimental investigation was carried out characterizing the constituent materials and testing in flexure beams constituted by two portions of beams connected in the middle with the joint proposed. Connections having different characteristics in terms of thickness of plates, number and type of bolts were utilized. Flexure tests allow one to determine the loaddeflection curves of the beam tested and the moment-rotation diagrams of the connections, highlighting the strength and the strain capacity of the joints. The proposed analytical model allows one to determine the moment-rotation relationship of the connections, pointing out the influence of the principal geometrical and mechanic characteristics of single constituents on the full properties of the joint.

• Steel and Composite Structures
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• v.4 no.6
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• pp.453-469
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• 2004

In this article, a genetic algorithm based optimum design method is presented for non-linear steel frames with semi-rigid connections. The design algorithm obtains the minimum weight frame by selecting suitable sections from a standard set of steel sections such as European wide flange beams (i.e., HE sections). A genetic algorithm is employed as optimization method which utilizes reproduction, crossover and mutation operators. Displacement and stress constraints of Turkish Building Code for Steel Structures (TS 648, 1980) are imposed on the frame. The algorithm requires a large number of non-linear analyses of frames. The analyses cover both the non-linear behaviour of beam-to-column connection and $P-{\Delta}$ effects of beam-column members. The Frye and Morris polynomial model is used for modelling of semi-rigid connections. Two design examples with various type of connections are presented to demonstrate the application of the algorithm. The semi-rigid connection modelling results in more economical solutions than rigid connection modelling, but it increases frame drift.