• Steel and Composite Structures
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• v.32 no.1
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• pp.37-57
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• 2019

This paper presents experimental and analytical studies to evaluate the cyclic behaviour of Circular Reinforced Concrete column Steel beam (CRCS) connections. Two 3/4-scale CRCS specimens are tested under quasi-static reversed cyclic loading. Specimens were strengthened with a tube plate (TP) and a steel doubler plate (SDP). Furthermore; nine interior beam-through type RCS connections are simulated using nonlinear three-dimensional finite element method using ABAQUS software and are verified with experimental results. The results revealed that using the TP improves the performance of the panel zone by providing better confinement to the concrete. Utilizing the TP at the panel zone may absorb and distribute stress in this region. Results demonstrate that TP can be used instead of SDP. Test records indicate that specimens with TP, with and without SDP maintained their maximum strength up to 4% drift angle, satisfying the recommendation given by AISC341-2016 for composite special moment-resisting frames.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1033-1039
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• 2012

In this paper, a simple and robust algorithm is proposed for detecting each steel plate from a image which contains several steel plates. Steel plate is characterized by line edge, so line detection is a fundamental task for analyzing and understanding of steel plate images. To detect the line edge, the proposed algorithm uses the small eigenvalue analysis. The proposed approach scans an input edge image from the top left corner to the bottom right corner with a moving mask. A covariance matrix of a set of edge pixels over a connected region within the mask is determined and then the statistical and geometrical properties of the small eigenvalue of the matrix are explored for the purpose of straight line detection. Using the detected line edges, each plate is determined based on the directional information and the distance information of the line edges. The results of the experiments emphasize that the proposed algorithm detects each steel plate from a image effectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.1
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• pp.130-140
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• 2007

Fiber-sheet and steel-plate strengthening methods have been mainly used for strengthening the RC structures. However, recently the application of these two methods have dramatically decreased due to premature debonding failure between concrete surface and fiber-sheet and heavy self-weight of steel-plate. This article presents experimental results of shear behavior in RC beams strengthened with GSP(Glass fiber-Steel composite Plate). The thin steel plate in GSP makes usage of the anchoring system possible, which could delay or prevent the premature debonding failure. Three reference beams and 60 strengthened beams with GSP were tested. The experimental results showed that strengthened beams with GSP considerably increased in shear capacity compared with the reference beams.

• Structural Engineering and Mechanics
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• v.86 no.3
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• pp.385-397
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• 2023

This study presents an experiment and analysis to compare the seismic behavior of full-scale reinforced concrete beam-column joint strengthened by prestressed steel strips, externally bonded steel plate, and CFRP sheets. For experimental investigation, five specimens, including one joint without any retrofitting, one joint retrofitted by externally bonded steel plate, one joint retrofitted by CFRP sheets, and two joints retrofitted by prestressed steel strips, were tested under cyclic-reserve loading. The failure mode, strain response, shear deformation, hysteresis behavior, energy dissipation capacity, stiffness degradation and damage indexes of all specimens were analyzed according to experimental study. It was found that prestressed steel strips, steel plate and CFRP sheets improved shear resistance, energy dissipation capacity, stiffness degradation behavior and reduced the shear deformation of the joint core area, as well as changed the failure pattern of the specimen, which led to the failure mode changed from the combination of flexural failure of beams and shear failure of joints core to the flexural failure of beams. In addition, the beam-column joint retrofitted by steel plate exhibited a high bearing capacity, energy consumption capacity and low damage index compared with the joint strengthened by prestressed steel strip, and the prestressed steel strips reinforced joint showed a high strength, energy dissipation capacity and low shear deformation, stirrups strains and damage index compared to the CFRP reinforced joint, which indicated that the frame joints strengthened with steel plate exhibited the most excellent seismic behavior, followed by the prestressed steel strips.

• Journal of the Society of Disaster Information
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• v.12 no.1
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• pp.54-61
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• 2016

The use of advanced composite materials in strengthening and repair of existing structures is increasing rapidly. This paper describes an effectiveness of a bonding of carbon fiber reinforced sheets to corroded steel members for the repair. Three types of surface treatment, what we call cleaning, of corroded plate are chosen as parameters. They are "without cleaning","removal of painting by brushing" and "complete removal of painting". From the experimental study, the following findings are obtained. 1) When the steel plate is subjected to tensile force, carbon fiber sheets adhered to the painted steel gives a higher strength against peeling compared to that of the plate without painting, 2) The grade of surface treatment, or cleaning of the corroded steel plate affects the strengthening effect.

• Steel and Composite Structures
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• v.19 no.4
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• pp.877-895
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• 2015

Connections to circular hollow steel sections (CHS) are considered one of the most complex and time consuming connections in steel construction. Such connections are usually composed of gusset plates welded to the outside of the steel tube or penetrating the steel tube. Design guides, accounting for the effect of connection configuration on the strength of the connection, are not present. This study aims to investigate, through experimental testing and a parametric study, the influence of connection configuration on the strength of one sided branch plate-to-CHS members. A notable effect was observed on the behavior of the connections due to its detailing changes with respect to capacity, failure mode, ductility, and stress distribution. A parametric study is performed using the calibrated analytical model to include a wider range of parameters. The study involves 26 numerical analyses of finite element models including parameters of the diameter-to-thickness (D/t) ratio, length of gusset plate, and connection configuration. Accordingly, a modification to the formulas provided by the current design recommendations was suggested to include connection configuration effects for the one sided branch plate-to-CHS members.

• Journal of Welding and Joining
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• v.3 no.1
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• pp.11-21
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• 1985

The line heating is a thermoplastic working technique which is used in bending work of steel plate and in correcting the distortion of welded structure. This method is considerably effective when the water-cooling is followed. In this study, an investigation was accomplished to find the effects on the change of material properties when the line heating was applied on the high tensile steel plate of 50kg/mm^2$ grade. Some steel plates were heated to various temperatures and then cooled with water or in the air. In this study, the author measured the angular distortion continuously during line heating to find out the relation between the bending efficiency and heating or water-cooling temperature. Furthermore, its material properties were examined by the V-notch Charpy impact test, the microscope observation and the Vickers hardness test. As results, the followings were clarified. (1) The amount of angular distortion increases as the heating temperature or the water-cooling temperature rises. (2) When the steel plate is heated between 700.deg. C and 900.deg. C, and then is water-cooled over 700.deg. C, some brittle structure is observed. But if the temperature of water-cooling is below 700.deg. C, no brittle one is found. (3) When the steel plate is heated over 800.deg. C and is cooled in the air, there is no unfavrable effect.

• Steel and Composite Structures
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• v.37 no.6
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• pp.741-759
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• 2020

Steel plate-concrete composite slabs provide attractive features, such as more effective loading transfer, and more cost-effective stay-in-place forms, thereby enabling engineers to design more high-performance light structures. Although significant studies in the literatures have been directed toward designing and implementing the steel plate-concrete composite beams, there are limited data available for understanding of the composite slabs. To fill this gap, nine the composite slabs with different variables in this study were tested to unveil the impacts of the critical factors on the ultimate strength behavior. The key information of the findings included sample failure modes, crack pattern, and ultimate strength behavior of the composite slabs under either four-point or three-point loading. Test results showed that the failure modes varied from delamination to shear failures under different design factors. Particularly, the shear stud spacing and thicknesses of the concrete slabs significantly affected their ultimate load-carrying capacities. Moreover, an analytical model of the composite slabs was derived for determining their ultimate load-carrying capacity and was well verified by the experimental data. Further extensive parametric study using the proposed analytical methods was conducted for a more comprehensive investigation of those critical factors in their performance. These findings are expected to help engineers to better understand the structural behavior of the steel plate-concrete composite slabs and to ensure reliability of design and performance throughout their service life.

• Structural Engineering and Mechanics
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• v.89 no.2
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• pp.155-170
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• 2024

Several types of column-beam connections are used in the design of steel structures. This situation causes different cross-section effects and, therefore, different displacements and deformations. In other words, connection elements such as welds, bolts, continuity plates, end plates, and stiffness plates used in steel column-beam connections directly affect the section effects. This matter reveals the necessity of knowing the steel column-beam connection behaviours. In this article, behaviours of bolted column-beam connection with end plate widely used in steel structures are investigated comparatively the effects of the stiffness plates added to the beam body, the change in the end plate thickness and bolt diameter. The results obtained reveal that the moment and force carrying capacity of the said connection increases with the increase in the end plate thickness and bolt diameter. In contrast, it causes the other elements to deform and lose their capacity. This matter shows that optimum dimensions are very important in steel column-beam connections. In addition, it has been seen that adding a stiffness plate to the beam body part positively contributes to the connection's moment-carrying capacity.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.133-140
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• 2008

The Corrugated steel plate structure(CPS) can be applied to construction sites with various purposes, and the merits of CPS such as economical efficiency and swiftness can be utilized when it is constructed properly in consideration of its characteristics. However, in Korea, since the history of corrugated steel plate culvert is relatively short, there are not enough design standards. This research is prepared for finding out the causes through examining and analyzing the problems based on the examples from the existing constructions. Moreover, this study can be utilized in preparing designs and design standards of corrugated steel plate culvert in the future and devising prevention measures and complementary measures by studying construction methods considering features of construction sites and circumstances, several points to be considered while carrying out construction works and prevention measures of a problem with the existing structures.