• Steel and Composite Structures
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• v.32 no.1
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• pp.111-126
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• 2019

This paper deals with experimental investigation and modeling of the static behavior of a novel RCS beam-column exterior joint. The studied joint detail is a through-column type in which an H steel profile totally embedded inside RC column is directly welded to the steel beam. The H steel profile was covered by two supplementary plates in the joint area in order to avoid the stirrups resisting shear in the joint area. Two full-scale through-column-type RCS joints were tested under static loading. The objectives of the tests were to examine the connection performance and to highlight the contribution of two supplementary plates on the shear resistance of the joint. A reliable nonlinear 3D finite element model was developed using ABAQUS software to predict the response and behavior of the studied RCS joint. An extensive parametric study was performed to investigate the influences of the stirrups, the encased profile length and supplementary plate length on the behavior of the studied RCS joint.

• Steel and Composite Structures
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• v.47 no.2
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• pp.203-216
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• 2023

The composite beam connections often encountered fracture failure in the welded bottom flange joint, and a bottom flange bolted connection has been proposed to increase the deformation ability of the bottom flange joint. The seismic performance of the bottom flange bolted composite beam connection was suffered from both the composite action of concrete slab and the asymmetric load transfer mechanisms between top and bottom beam flange joints. Thus, this paper presents a comprehensive numerical study on the working mechanism of the bottom flange bolted composite beam connections. Three available modelling methods and a new modelling method on the flange-stud-slab interactions were compared. The efficient numerical modeling method was selected and then applied to the parametric study. The influence of the composite slab, the bottom flange bolts, the shear composite ratio and the web hole shape on the seismic performance of the bottom flange bolted composite beam connections were investigated. A hogging strength calculation method was then proposed based on numerical results.

• Journal of Korean Society of Steel Construction
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• v.22 no.4
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• pp.305-312
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• 2010

The objective of this paper is to examine the structural performance of steel moment-resisting frames on the various connection details of Seismic Wide-flanged Beam-to-Rectangular Steel Tube Column connections. Although compared to an H-shaped steel tube, a rectangular steel tube has many advantages and is more efficient, its application is limited due to the lack of experience in using it and the connection details. Existing steel moment connections using the rectangular steel tube are mainly used through plate diaphragms. The processing of construction of the rectangular steel tube is so complicated that it is hard to apply it in the field. In this study, the structural performance and the earthquake capacity of the connection details that do not cut the rectangular steel tube column were investigated. A comparative analysis of the strength, rigidity, and energy absorption capacity of the welded connection details using an end-plate and a haunch was also performed.

• Journal of the Korean Society for Advanced Composite Structures
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• v.3 no.4
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• pp.27-37
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• 2012

The construction of a moment connection for a rectangular hollow section (RHS) column and a H-shaped beam is difficult because the RHS is a closed section. When a inner diaphragm is used for such a connection, in general, it is installed after cutting the HSS columns, which results in increased construction work. This paper suggests a new fabrication method to overcome such problems: An inner diaphragm is welded to inside a C-shaped section first, and then a column is fabricated by welding two C-shaped sections. This fabrication method is superior to a classic method in terms of constructibility. An experimental and a numerical study using Ansys 9.0 were performed in order to compare the strength of connections with respect to the presence of concrete, the corner shape of diaphragm, and the axis of loading. The experimental results including initial stiffness and ultimate loads are reported and the analytical results including load transfer mechanism, degree of stress concentration, and strain distribution are also reported.

• Steel and Composite Structures
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• v.11 no.3
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• pp.251-271
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• 2011

To make direct comparisons regarding the cyclic behavior of thin steel plate shear walls (TSPSWs) with different infill-to-boundary frame connections, two TSPSWs were tested under quasi-static conditions, one having the infill plate attached to the boundary frame members on all edges and the other having the infill plate connected only to the beams. Also, the bare frame that was used in the TSPSW specimens was tested to provide data for the calibration of numerical models. The connection of infill plates to surrounding frames was achieved through the use of self-drilling screws to fish plates that were welded to the frame members. The behavior of TSPSW specimens are compared and discussed with emphasis on the characteristics important in seismic response, including the initial stiffness, ultimate strength and deformation modes observed during the tests. It is shown that TSPSW specimens achieve significant ductility and energy dissipation while the ultimate failure mode resulted from infill plate fracture at the net section of the infill plate-to-boundary frame connection after substantial infill plate yielding. Experimental results are compared to monotonic pushover predictions from computer analysis using strip models and the models are found to be capable of approximating the monotonic behavior of the TSPSW specimens.

• Steel and Composite Structures
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• v.36 no.4
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• pp.447-462
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• 2020

The paper aims to investigate the mechanical mechanism and seismic effect of stiffeners in blind bolt endplate connection to CFST column. A precise 3D finite element model with considering the cyclic properties of concrete and steel materials was established, and the efficiency was validated through monotonic and cyclic test data. The deforming pattern and the seismic performance of the unstiffened and stiffened blind bolt endplate connections were investigated. Then a parametric analysis was conducted to analyze the contribution of stiffeners and the joint working behaviors with endplate under cyclic load. The joint stiffness classifications were compared and a supplement stiffness classification method was proposed, and the energy dissipation ability of different class connections were compared and discussed. Results indicated that the main deformation pattern of unstiffened blind bolt endplate connections was the local bending of end plate. The vertical stiffeners can effectively alleviate the local bending deformation of end plate. And influence of stiffeners in thin endplate and thick endplate was different. Based on the stiffness of external diaphragm welded connection, a more detailed rigidity classification was proposed which included the pin, semi-rigid, quasi-rigid and rigid connection. Beam was the main energy dissipation source for rigid connection. For the semi-rigid and quasi-rigid connection, the extended endplate, stiffeners and steel beam would all participate in the energy dissipation.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.377-384
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• 2011

Recently, for the purpose of reducing work terms and improving performance for construction work, various methods in structure field were developed. This included the HRC system which is applicable to a typical structure (e.g., parking and office building). The HRC system introduced the Gerber Joint to raise structural efficiency and used connection plate to bolt HRC composite beam to H beam in the construction field. In this research, the experimental tests for six specimens, which were in the same field conditions, were conducted with several parameters such as the length and height of the connection plate and the number of stub bolts. The test result was compared with those made by current design codes for the deflection and strains of the main bar. Within the given load, the integration of concrete in beam and connection plate, welded with stud bolts, was verified.

• Journal of Welding and Joining
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• v.17 no.1
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• pp.82-87
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• 1999

The basic remote sleeve repair-welding technology by the pulsed Nd:YAG laser for increasing the lifetime of the steam generator tube in a nuclear power plant has been developed. The relationship between the connection width and welding parameters have been investigated for the fundamental research to apply the sleeve-repair-welding technique to the nuclear industry. The Inconel 600 tube and Inconel 690 sleeve used for high temperature and high pressure service were welded as round lap welding by Nd:YAG laser. It was observed that the tensile shear strength, 340MPa of the welded specimen is equivalent to about 60% of that of the base metal (Inconel 600), 550MPa. The difference between the hardness of the base metal and that of the laser welds was about 10%. Ductile fracture was partly occurred in the weld but the cracking has not been observed. In spite of absence of the crack, the strength of welds was not sufficient in terms of the tensile shear strength.

• Laser Solutions
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• v.14 no.4
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• pp.1-8
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• 2011

This study is about laser welded joints in order to replace the traditional screw connection of a differential gear and its case in the differential gear assembly. Screws are usually used to join these parts. But the screws take up weight and space. So we needed to improve the joining method. In the welding of a differential gear and its case, the quality is much harder to control, because the high carbon contents of the two components results in cold cracks. But a new method that adds wire allows these materials to be joined. Additionally, more distortions generally occurs in the welded joints than in screws. We tried to prove that laser welding is an available method for joining these parts through the measurement and various tests.

• Coupled systems mechanics
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• v.11 no.3
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• pp.267-284
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• 2022

Due to the high usage of ABS in industries, such as aerospace, auto, recreational devices, boat, submarines, etc., the purpose of this project was to find a way to weld this material, which gives advantages, such as affordable, high speed, and good connection quality. In this experimental project, the friction welding method was applied with parameters such as numerical control (NC) machine with two different speeds and three cross-sections, including a flat surface, cone, and step. After the end of the welding process, samples were then applied for both tensile and bending tests of materials, and the results showed that, with increasing the machining velocity Considering of samples, the friction of the surface increased and then caused to increase in the surface temperature. Considering mentioned contents, the melting temperature of composite materials increased. This can give a chance to have a better combination of Nanomaterial to base melted materials. Thus, the result showed that, with increasing the weight percentage (wt %) of Nanomaterials contents, and machining velocity, the mechanical behavior of welded area for all three types of samples were just increased. This enhancement is due to the better melting process on the welded area of different Nano contents; also, the results showed that the shape of the welding area could play a significant role, and by changing the shape, the results also changed drastically.A better shape for the welding process was dedicated to the step surface.