• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.68-75
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• 1995

In recent year, column member is used for square hollow section(5.H.5) and beam member is used for H-section. But 5.H.5 column has vulnerability because of low flexural stiffness between column and beam connection joints. To reinforce this vulnerability, 5.H.5 column filled with concrete and concrete slab connection compounded with H-beam is developed in many ways. In this paper, modelling of predicting behavior of various types of connections is studied using finite element method. k order to simulate the actual behavior, a three-dimensional modelling is used. A simple efficient contact algorithm with a new gap element is employed to simulate the interaction between 5.H.5 column and concrete, The modelling result$ are compared with the experimental results.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.37-40
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• 2008

The study is an experimental test on full-scale flat plate slab-column interior connection. The punching shear on the flat plate slab-column connection can bring about the reason of the brittle punching shear failure which may result of collapsing the whole structure. From the development of residential flat plate system, the shear reinforcement is developed for preventing the punching shear. For making sure of the punching shear capacity, developed for shear reinforcement in slab-column connection, the structural test is performed. The dimension of the slabs was 2620*2725*180mm with square column (600*800mm). The slabs were tested up to failure monotonic vertical shear forces. The presences of S/S bar and wire mesh substantially increased the punching shear capacity and the ductility of the slab-column connections.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.8
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• pp.393-400
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• 2016

Recently, there have been various researches on efficient and automatic analysis on urban environment methods that utilize the computer vision and machine learning technology. Among many new analyses, urban safety analysis has received a major attention. In order to predict more accurately on safety score and reflect the human visual perception, it is necessary to consider the generic and local information that are most important to human perception. In this paper, we use Double-column Convolutional Neural network consisting of generic and local columns for the prediction of urban safety. The input of generic and local column used re-sized and random cropped images from original images, respectively. In addition, a new learning method is proposed to solve the problem of over-fitting in a particular column in the learning process. For the performance comparison of our Double-column Convolutional Neural Network, we compare two Support Vector Regression and three Convolutional Neural Network models using Root Mean Square Error and correlation analysis. Our experimental results demonstrate that our Double-column Convolutional Neural Network model show the best performance with Root Mean Square Error of 0.7432 and Pearson/Spearman correlation coefficient of 0.853/0.840.

• Journal of Korean Society of Steel Construction
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• v.17 no.4 s.77
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• pp.459-467
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• 2005

This study focuses on the development of a new method of H-shaped beam-to-square column connection with an outer diaphragm and a field welding. The specific type of beam-to-column connection with an external stiffener, using field welding, is proposed. The structural behavior of this connection was examined experimentally. Two loading type tests were conducted under the experimental parameters given as details. First described was the symmetrical loading test, which supported both ends or a beam simply and applied a load from the column to the pend (What does this mean?) to investigate a fundamental characteristic of this connection. Further described was the anti-symmetrical loading test, which carried out simple support of the column'stop end and the column base, and applied a load from both ends of a beam to investigate the structural performance of this connection. From the results, it is clear that the external- stiffener-type connection proposed in this paper is the reliable connection method.

• Steel and Composite Structures
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• v.38 no.6
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• pp.637-656
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• 2021

The component-based method is widely used to analyze the initial stiffness of joint in steel structures. In this study, an analytical component model for determining the column face stiffness of square or rectangular hollow section (SHS/RHS) subjected to tension was established, focusing on endplate connections. Equations for calculating the stiffness of the SHS/RHS column face in bending were derived through regression analysis using numerical results obtained from a finite element model database. Because the presence of bolt holes decreased the bending stiffness of the column face, this effect was calculated using a novel plate-spring-based model through numerical analysis. The developed component model was first applied to predict the bending stiffness of the SHS column face determined through tests. Furthermore, this model was incorporated into the component-based method with other effective components, e.g., bolts under tension, to determine the tensile stiffness of the T-stub connections, which connects the SHS column, and the initial rotational stiffness of the joints. A comparison between the model predictions, test data, and numerical results confirms that the proposed model shows satisfactory accuracy in evaluating the bending stiffness of SHS column faces.

• Steel and Composite Structures
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• v.38 no.1
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• pp.103-120
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• 2021

This research examines the eccentric compression performance of composite columns composed of recycled aggregate concrete (RAC)-filled square steel tube and profile steel. A total of 17 specimens on the composite columns with different recycled coarse aggregate (RCA) replacement percentage, RAC strength, width to thickness ratio of square steel tube, profile steel ratio, eccentricity and slenderness ratio were subjected to eccentric compression tests. The failure process and characteristic of specimens under eccentric compression loading were observed in detail. The load-lateral deflection curves, load-train curves and strain distribution on the cross section of the composite columns were also obtained and described on the basis of test data. Results corroborate that the failure characteristics and modes of the specimens with different design parameters were basically similar under eccentric compression loads. The compression side of square steel tube yields first, followed by the compression side of profile steel. Finally, the RAC in the columns was crushed and the apparent local bulging of square steel tube was also observed, which meant that the composite column was damaged and failed. The composite columns under eccentric compression loading suffered from typical bending failure. Moreover, the eccentric bearing capacity and deformation of the specimens decreased as the RCA replacement percentage and width to thickness ratio of square steel tube increased, respectively. Slenderness ratio and eccentricity had a significantly adverse effect on the eccentric compression performance of composite columns. But overall, the composite columns generally had high-bearing capacity and good deformation. Meanwhile, the mechanism of the composite columns under eccentric compression loads was also analysed in detail, and the calculation formulas on the eccentric compression capacity of composite columns were proposed via the limit equilibrium analysis method. The calculation results of the eccentric compression capacity of columns are consistent with the test results, which verify the validity of the formulas, and the conclusions can serve as references for the engineering application of this kind of composite columns.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.475-480
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• 1998

The composite framed structures, consisting of RC columns and steel beams more popular in korea because of their efficiency and quality. However the force transfer mechanisms between the column and beam may by very complicated since the materials of columns and beams are different. This study develops "the column penetration joint" which the web of steel beam doesn't penetrate and which could improve the strength, deformation, and energy dissipation capacities compared to existing composite joints. It is the concrete-filled square tube joint with the exterior diaphragms and the cruciform stiffening plates. This study evaluated the strength of RC column penetration to steel beam connection by analyzing the results of partial experiments, and reviewed the applicability the strength formula through the comparison of tested results of joint experiment.

• Steel and Composite Structures
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• v.28 no.4
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• pp.449-460
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• 2018

This paper reports the experimental results of three through bolt beam-column connections under pure shear forces using modified push-out tests. The investigated specimens include extended end-plates and six through-bolts connecting square concrete-filled steel tubular column (S-CFST) to steel beams. The main goal of this study is to investigate if and how the mechanical shear connectors, such as steel angles and stud bolts, contribute to the shear transfer mechanisms in the steel-concrete interface of the composite column. The contribution of shear studs and steel angles to improve the shear resistance of steel-concrete interface in through-bolt connections was investigated using tests. The results showed that their contribution is not significant when the beam-column connection is included in the push-out tests. The specimens failed by pure shear of the long bolts, and the ultimate load can be predicted using the shear resistance of the bolts under shear forces. The predicted values of load allowed obtaining a good agreement with the tests results.

• Journal of Korean Society of Steel Construction
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• v.11 no.4 s.41
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• pp.385-395
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• 1999

Square hollow section columns and H-section beams have recently been increasing1y used. Rigid column-beam connections cannot be made for the structural system and thus some measures to improve the rotational stiffness of connections should be developed. For this purpose, several types of connections. such as H-section beams connected to concrete-filled square hollow section columns, have been contrived and put to experiment. Since the experimental works are usually difficult and expensive. Particularly test of all the types of connections with similar behavior may not be feasible. Instead, the numerical analysis will be adopted predict the flexural stiffness of connections. In this work, FEM modeling techniques are examined and parametric analysis study has been carried out. The major parameters considered are concrete strength, thickness of steel column, magnitude and eccentricity of axial forces.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.3
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• pp.326-338
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• 2017

The Vortex-induced Motions (VIM) phenomenon of semi-submersibles is relevant for the fatigue life of moorings and risers. Model tests regarding the VIM behavior of a semi-submersible with four square columns were conducted in order to investigate the effects of the current incidence and the aspect ratio of the immerged column. The experimental results show that the largest transverse amplitudes are around 70% of the column width at $30^{\circ}$ and $45^{\circ}$ incidences in a range of reduced velocities from 5 to 8 when the aspect ratio of the immerged column is 1.90. The largest yaw motion occurs at $0^{\circ}$ incidence with the peak value around $4.5^{\circ}$. Similar characteristics of the VIM response are observed for the semi-submersible with aspect ratios of 1.90 and 1.73. When the aspect ratio decreases 50% to 0.87, 30% decrease in the peak transverse amplitudes can be seen.