• 에너지공학
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• 제24권4호
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• pp.71-80
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• 2015

PVC 프레임의 취약한 강도를 보완하기 위해 사용되는 철재 보강재는 상대적으로 높은 열전도 특성으로 인해 PVC 프레임의 전체적인 열 성능을 떨어뜨리는 역할을 한다. 본 연구는 철재 보강재의 타공을 통해 표면적을 줄임으로서 전열 면적의 감소를 통한 열저항 특성을 개선하고, 감소된 만큼 두께를 높임으로서 타공으로 인한 강도 저하를 보완하였다. 이에 대한 성능을 평가하기 위해 PVC frame, PVC frame + original steel stiffener, PVC frame + 30% perforated steel stiffener, PVC frame + 50% perforated steel stiffener, PVC frame + 65% perforated steel stiffener 등 5개의 시험체를 구성하였으며, 시험 방법은 수식과 시뮬레이션에 의한 방법을 적용하였다. 시험 결과 PVC frame + 65% perforated steel stiffener이 열저항 특성과 강도특성에서 가장 높은 것으로 평가되었다.

• 국제강구조저널
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• 제18권4호
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• pp.1464-1469
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• 2018

Steel frames with ductile connections have good seismic performance under strong earthquake, they are now popular for high seismic design. In order to simplify the process of numerical analysis of the steel frames with ductile connections, simplified connection models are introduced, two types of springs are placed in the simplified connection model, which can simulate deformation of the panel zone and members. 6-story-3-bay steel frames with ductile connections are simplified and carried out modal analysis, fundamental periods of the frames predicted by finite-element analysis for simplified steel frame models were compared to the results for actual frame models. 2-story steel frame with reduced beam section connections is simplified and carried out pseudo-static analysis, hysteretic curves and skeleton curves of the frame obtained by finite-element analysis for simplified steel frame model are compared to test results. The comparison show that the difference between them is small, it is reliable and effective to predict mechanical properties of the steel frame with ductile connection by finite-element analysis of simplified steel frame model.

• Steel and Composite Structures
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• 제46권6호
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• pp.857-865
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• 2023

This study aimed to develop a seismic retrofit technique using a steel frame which can be easily transported and assembled on site. This enables the retrofit steel frame to be easily attached to an existing structure minimizing the unwanted gap between the structure and the steel frame assembly. A one-story one-bay RC frame was tested with and without seismic retrofit using the proposed steel frame to verify the seismic retrofit effect of the proposed system, and an analysis model was developed in Opensees for seismic performance evaluation of a case study soft first-story model structure retrofitted with the developed steel frame assembly. Seismic performance of the model structure was also evaluated considering soil structure interaction effect. The experimental study confirmed that the proposed seismic retrofit system can be applied effectively to improve the seismic performance of framed structures. Time history analysis results of the model structure showed that the proposed steel frame assembly was effective in increasing the seismic load resisting capacity of the soft first-story structure. However more steel frame assemblies were required to satisfy the given performance limit state of the model structure located on weak soil due to the negative soil-structure interaction effect.

• 한국공간구조학회논문집
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• 제23권1호
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• pp.77-84
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• 2023

In this study, the performance evaluation of the RC frame specimen (RV2) which was strengthened by a steel frame and a steel damper with the lateral deformation prevention details proceeded. The comparison objects are bare frame specimen (BF), RV2 and AWD, where AWD is a specimen reinforced with steel damper and aramid fiber sheets. In the evaluation of envelope curve, stiffness degradation, and energy dissipation capacity, RV2 was evaluated to have excellent capacity as a whole. To evaluate the strengthening effect of the steel frame based on the maximum strength and energy dissipation capacity, it was evaluated to have a 38% of the RV2's capacity.

• Steel and Composite Structures
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• 제41권6호
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• pp.861-871
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• 2021

This study aims at investigating the hysteretic performance of a novel composite wall panel fabricated by infilling aerated concrete blocks into a novel light-steel frame used for low-rise residential buildings. The novel light-steel frame is consisted of two thin-wall rectangular hollow section columns and a truss-beam assembled using patented U-shape connectors. Two bare light-steel frames and two composite wall panels have been tested to failure under horizontal cyclic loading. Hysteretic curves, lateral resistance and stiffness of four specimens have been investigated and analyzed. Based on the testing results, it is found that the masonry infill can significantly increase the lateral resistance and stiffness of the novel light-steel frame, about 2.3~3 and 21.2~31.5 times, respectively. Failure mode of the light-steel frame is local yielding of the column. For the composite wall panel, firstly, masonry infill is crushed, subsequently, local yielding may occur at the column if loading continues. Hysteretic curve of the composite wall panel obtained is not plump, implying a poor energy dissipation capacity. However, the light-steel frame of the composite wall panel can dissipate more energy after the masonry infill is crushed. Therefore, the composite wall panel has a much higher energy dissipation capacity compared to the bare light-steel frame.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.361.1-361
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• 2002

Coupling adjacent steel frame using elastic dampers fer control of response to low and moderate dynamic event is investigated in this paper. The complex modal superposition method is first used to determine dynamic characteristic, mainly modal damping ratio and modal frequency, of damper linked linear adjacent steel frame for fractical use. Dynamic response of steel frame linked by hydraulic-excitation method. (omitted)

• Steel and Composite Structures
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• 제22권2호
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• pp.235-255
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• 2016

This paper experimentally investigated the behavior of steel frame structures of traditional-style buildings subjected to combined constant axial load and reversed lateral cyclic loading conditions. The low cyclic reversed loading test was carried out on a 1/2 model of a traditional-style steel frame. The failure process and failure mode of the structure were observed. The mechanical behaviors of the steel frame, including hysteretic behaviors, order of plastic hinges, load-displacement curve, characteristic loads and corresponding displacements, ductility, energy dissipation capacity, and stiffness degradation were analyzed. Test results showed that the Dou-Gong component (a special construct in traditional-style buildings) in steel frame structures acted as the first seismic line under the action of horizontal loads, the plastic hinges at the beam end developed sufficiently and satisfied the Chinese Seismic Design Principle of "strong columns-weak beams, strong joints-weak members". The pinching phenomenon of hysteretic loops occurred and it changed into Z-shape, indicating shear-slip property. The stiffness degradation of the structure was significant at the early stage of the loading. When failure, the ultimate elastic-plastic interlayer displacement angle was 1/20, which indicated high collapse resistance capacity of the steel frame. Furthermore, the finite element analysis was conducted to simulate the behavior of traditional-style frame structure. Test results agreed well with the results of the finite element analysis.

• Steel and Composite Structures
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• 제50권3호
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• pp.337-345
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• 2024

This research proposed a particle swarm optimization (PSO) based seismic retrofit design of moment frame structures using a steel frame assembly. Two full scale specimens of the steel frame assembly with different corner details were attached to one-story RC frames for seismic retrofit, and the lateral load resisting capacities of the retrofitted frames subjected to cyclic loads were compared with those of a bare RC frame. The open source software framework Opensees was used to develop an analytical model for validating the experimental results. The developed analytical model and the optimization scheme were applied to a case study structure for economic seismic retrofit design, and its seismic performance was assessed before and after the retrofit. The results show that the developed steel frame assembly was effective in increasing seismic load resisting capability of the structure, and the PSO algorithm could be applied as convenient optimization tool for seismic retrofit design of structures.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.96-97
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• 2014

Green Frame is a column-beam structure built by steel frame joints embedded in the columns and beams. Here, the steel frame embedded in the columns and beams is not a standardized product, instead it needs to be order-produced. The quantity for each steel frame size should be calculated to estimate the quantity of steel frames to be manufactured. However, it is highly time-consuming and requires a lot of effort in calculating the quantity of steel frames, for there are a wide range of steel frame types that are embedded in the columns and beams. To solve this problem, the study proposes an algorithm for calculation of the amount of steel frames with ease and promptness. When a program is developed using the algorithm proposed in the study in connection to the information on precast concrete members prepared in the design phase, it is anticipated that the manpower required as well as the manufacturing time will be decreased.

• Steel and Composite Structures
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• 제20권3호
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• pp.719-729
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• 2016

There are great needs of simple but reliable mechanical nonlinear behavior analysis and performance evaluation method for frames constructed by steel and concrete composite beams or columns when the structures subjected extreme loads, such as earthquake loads. This paper describes an approach of simplified macro-modelling for composite frames consisting of steel-concrete composite beams and CFST columns, and presents the performance evaluation procedure based on the pushover nonlinear analysis results. A four-story two-bay composite frame underground is selected as a study case. The establishment of the macro-model of the composite frame is guided by the characterization of nonlinear behaviors of composite structural members. Pushover analysis is conducted to obtain the lateral force versus top displacement curve of the overall structure. The identification method of damage degree of composite frames has been proposed. The damage evolution and development of this composite frame in case study has been analyzed. The failure mode of this composite frame is estimated as that the bottom CFST columns damage substantially resulting in the failure of the bottom story. Finally, the seismic performance of the composite frame with high strength steel is analyzed and compared with the frame with ordinary strength steel, and the result shows that the employment of high strength steel in the steel tube of CFST columns and steel beam of composite beams benefits the lateral resistance and elasticity resuming performance of composite frames.