• Journal of Korean Society of Steel Construction
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• v.14 no.1
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• pp.59-67
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• 2002

The ultimate strength testing of a two-story, single-bay, and sway allowed space steel frame was performed. Considering a majority of large-scale frame tests in the past, only two-dimensional frames were experimentally studied. Therefore, three-dimensional experiment is needed to extend the knowledge of this field. The steel frame subjected to non-proportional vertical and horizontal load was tested. The load-displacement curve of the test frame is provided. The experiment results are useful for verification of the three-dimensional numerical analysis. The results obtained from 3D non-linear analysis using ABAQUS were compared with experimental data.

• Steel and Composite Structures
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• v.23 no.2
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• pp.173-186
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• 2017

Conceptual configuration and seismic performance of high-rise steel frame-brace structure are studied. First, the topology optimization problem of minimum volume based on truss-like material model under earthquake action is presented, which is solved by full-stress method. Further, conceptual configurations of 20-storey and 40-storey steel frame-brace structure are formed. Next, the 40-storeystructure model is developed in Opensees. Two common configurations are utilized for comparison. Last, seismic performance of 40-storey structure is derived using nonlinear static analysis and nonlinear dynamic analysis. Results indicate that structural lateral stiffness and maximum roof displacement can be improved using brace. Meanwhile seismic damage can also be decreased. Moreover, frame-brace structure using topology optimization is most favorable to enhance lateral stiffness and mitigate seismic damage. Thus, topology optimization is an available way to form initial conceptual configuration in high-rise steel frame-brace structure.

• Earthquakes and Structures
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• v.17 no.1
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• pp.39-48
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• 2019

This paper presents an experimental study on a 1/2 scale steel frame with archaized-style under the pseudo-dynamic loading. Four seismic waves, including El Centro wave, Taft wave, Lanzhou wave and Wenchuan wave, were input during the test. The hysteresis characteristic, energy dissipation acceleration response, displacement response, strength, stiffness and strain were analyzed. Based on the experiment, the elastoplastic dynamic time-history analysis was carried out with the software ABAQUS. The stress distribution and failure mode were obtained. The results indicate that the steel frame with archaized-style was in elastic stage when the peak acceleration of input wave was no more than 400 gal. Under Wenchuan wave with peak acceleration of 620 gal, the steel frame enters into the elastoplastic stage, the maximum inter-story drift was 1/203 and the bearing capacity still tended to increase. During the loading process, Dou-Gong yielded first and played the role of the first seismic fortification line, and then beam ends and column bottom ends yielded in turn. The steel frame with archaized-style has good seismic performance and meets the seismic design requirement of Chinese code.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.4-5
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• 2020

The research presented in this paper is subject to RC frame that increases seismic capacity by attaching DT(Double T type) steel frame to reinforced concrete column. The object of this study is not only to build experimental database providing necessary information for retrofit column but also to formulate modeling parameters of RC frame retrofitted by DT steel frame through comparing analysis for analytical model predicting inelastic behavior of reinforced concrete members.

• Journal of the Earthquake Engineering Society of Korea
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• v.17 no.6
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• pp.293-303
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• 2013

This paper deals with steel braced frame as increasing the lateral strength and ductility in order to seismic retrofit of existing buildings and discusses the designing criteria and calculation method of retrofitted buildings. The addition of steel braced frame can be effective for increasing the lateral strength and ductility of existing buildings. However, There is a problem in utilizing this method. It is the approach to provide an adequate connection between the existing RC frame and the installed steel braced frame, because global strength by failure mode(three type) depends on detail of connection and strength of existing RC frame. So, the designer must be confirmed if it satisfies the required performance or not. Failure mode of type I is the most appropriate for increasing the lateral strength and ductility. Seismic performance evaluation and strength calculation of seismic retrofit are performed by guideline by KISTEC(Korea Infrastructure Safety & Technology)'s "seismic performance evaluation and rehabilitation of existing buildings" and Japan Building Disaster Prevention Association. Buildings are modeled and non-linear pushover analysis are performed using MIDAS program.

• 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.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.4
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• pp.219-223
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• 2002

The actual behavior of joint is traditionally disregarded in steel frame design. In fact, the structural analysis of steel frames is generally carried out by assuming that joints fulfil the ideal condition of either a hinge or a fixed-end restraints. In this way, calculations are made somewhat simpler, but the structural model is not able to reflect the actual structural response. Therefore, steel frame classification system for estimation or analysis about behavior of steel frame should be established, and range that each connections belongs should be divided definitely. This research presents realistic and practical moment-rotation relation through investigation and analysis of steel frame beam-to-column classification system.

• Coupled systems mechanics
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• v.7 no.5
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• pp.555-581
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• 2018

The moment-resistant steel frames are frequently used as a load-bearing structure of buildings. Global response of a moment-resistant frame structure strongly depends on connections behavior, which can significantly influence the response and load-bearing capacity of a steel frame structure. The analysis of a steel frame with included joints behavior is the main focus of this work. In particular, we analyze the behavior of two connection types through experimental tests, and we propose numerical beam model capable of representing connection behavior. The six experimental tests, under monotonic and cyclic loading, are performed for two different types of structural connections: end plate connection with an extended plate and end plate connection. The proposed damage-plasticity model of Reissner beam is able to capture both hardening and softening response under monotonic and cyclic loading. This model has 18 constitutive parameters, whose identification requires an elaborate procedure, which we illustrate in this work. We also present appropriate loading program and arrangement of measuring equipment, which is crucial for successful identification of constitutive parameters. Finally, throughout several practical examples, we illustrate that the steel structure connections are very important for correct prediction of the global steel frame structure response.

• Steel and Composite Structures
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• v.22 no.5
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• pp.1055-1071
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• 2016

The paper presents an innovative steel moment frame with the replaceable reinforced concrete wall panel (SRW) structural system, in which the replaceable concrete wall can play a role to increase the overall lateral stiffness of the frame system. Two full scale specimens composed of the steel frames and the replaceable reinforced concrete wall panels were tested under the cyclic horizontal load. The failure mode, load-displacement response, deformability, and the energy dissipation capacity of SRW specimens were investigated. Test results show that the two-stage failure mode is characterized by the sequential failure process of the replaceable RC wall panel and the steel moment frame. It can be found that the replaceable RC wall panels damage at the lateral drift ratio greater than 0.5%. After the replacement of a new RC wall panel, the new specimen maintained the similar capacity of resisting lateral load as the previous one. The decrease of the bearing capacity was presented between the two stages because of the connection failure on the top of the replaceable RC wall panel. With the increase of the lateral drift, the percentage of the lateral force and the overturning moment resisted by the wall panel decreased for the reason of the reduction of its lateral stiffness. After the failure of the wall panel, the steel moment frame shared almost all the lateral force and the overturning moment.

• Earthquakes and Structures
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• v.16 no.1
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• pp.97-107
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• 2019

The frame structures investigated in this paper is composed of Concrete encased columns with L-shaped steel section and steel beams. The seismic behavior of this structural system is studied through experimental and numerical studies. A 2-bay, 3-story and 1/3 scaled frame specimen is tested under constant axial loading and cyclic lateral loading applied on the column top. The load-displacement hysteretic loops, ductility, energy dissipation, stiffness and strength degradation are investigated. A typical failure mode is observed in the test, and the experimental results show that this type of framed structure exhibit a high strength with good ductility and energy dissipation capacity. Furthermore, finite element analysis software Perform-3D was conducted to simulate the behavior of the frame. The calculating results agreed with the test ones well. Further analysis is conducted to investigate the effects of parameters including concrete strength, column axial compressive force and steel ratio on the seismic performance indexes, such as the elastic stiffness, the maximum strength, the ductility coefficient, the strength and stiffness degradation, and the equivalent viscous damping ratio. It can be concluded that with the axial compression ratio increasing, the load carrying capacity and ductility decreased. The load carrying capacity and ductility increased when increasing the steel ratio. Increasing the concrete grade can improve the ultimate bearing capacity of the structure, but the ductility of structure decreases slightly.