• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.72-84
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• 2016

The conventional brace system is generally accepted as the lateral load resisting system for steel structures due to efficient story drift control and economic feasibility. But lateral stiffness of the structure decreases when buckling happens to the brace in compression, so that it results in unstable structure with unstable hysteresis behavior through strength deterioration. Buckling restrained brace(BRB) system, in which steel core is confined by mortar/concrete-filled tube, represents stable behavior in the post-yield range because the core's buckling is restrained. So, seismic performance of BRB is much better than that of conventional brace system in point of energy absorption capacity, and it is applied the most in high seismicity regions as damper element. BRBs with various shaped-sections have been developed across the globe, but the shapes experimented in Korea are now quite limited. In this study, we considered built-up type of restraining member made up of precast reinforcement concrete and the steel core. we experimented the BRB according to AISC(2005) and evaluated seismic performances and hysteresis characteristics.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3A
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• pp.149-160
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• 2012

Corrugated steel plates have several advantages such as high resistance for shear without stiffeners, minimization of welding process, and high fatigue resistance. To take advantage of these benefits, several researchers have attempted to use corrugated steel plate as a web of I-girders. The lateral-torsional buckling is the major design aspect of such I-girders. However, lateral-torsional buckling of the I-girder with corrugated steel webs still needs to be investigated especially for a real loading condition such as non-uniform bending. This paper investigated the lateral-torsional buckling strength of the I-girder with corrugated steel webs under linear moment gradient by using finite element analysis. From the results, it was found that the buckling behavior of the I-girder with corrugated steel webs differed depending on the number of periods of the corrugation. Also, a simple equation for the moment gradient correction factor of the I-girder with corrugated steel webs was suggested. The inelastic lateral-torsional buckling strength of the I-girder with corrugated steel webs was then discussed based on current design equations for ordinary I-girders and the results of finite element analysis.

• ETRI Journal
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• v.14 no.1
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• pp.108-117
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• 1992

광통신 시스팀에서 신호접속용으로 사용되는 광커넥터의 결합기구 중 세라믹 페룰-슬리브의 정렬기구에서 발생하는 성능저하 현상을 다루었다. 성능저하 현상으로 페룰 단면연마시 발생하는 Vertex Eccentricty, 좌굴현상, 환경에 따른 탄성 및 응력의 변화, 마모, 피로파괴 등에 대한 이론적인 배경과 실험결과를 토대로 특성에 대한 영향을 분석하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.2
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• pp.37-46
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• 2009

In this study, the seismic performance of the Buckling Restrained Knee Bracing (BRKB) system was evaluated through a pin-connected 1-bay 1-story frame. The BRKB system using a bolted channel section developed was composed of a steel plate as a load-resisting core member and two channel sections as a restrainment of the local and global buckling of the core plate. The main purpose of the BRKB system is to be used as an effective tool to re-strengthen/rehabilitate old low- and mid-rise RC frame buildings, which do not have enough seismic resistance to earthquake loadings. The main variables for the test specimens were the size of the core plates, stiffeners and the use of guide plates. The test results showed that the size of the core plate, which was the main element for the load-resisting member, was the most important parameter to achieve ductile behavior under tension as well as compression, until the maximum displacement exceed twice the design drift limit given by the AISC Seismic Provisions.

• Journal of Korean Society of Steel Construction
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• v.21 no.2
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• pp.145-154
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• 2009

This study discusses the inelastic behavior of single-layer latticed dome, which consists of a tubular truss member and newly proposed joint sections, through a loading test on a scaled-down structure. The loading test was performed under displacement control conditions, using loading transfer system for the same value of point loads on all joints. The maximum applied load was nearly 1.6 times of the design load, and structural failure occurred after exceeding the compressive yielding in some members. Structural displacement was maintained up to the limit of the oil jack. The behavior of the latticed dome from the loading test was analyzed according to the order of loading steps.

• Journal of Korean Society of Steel Construction
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• v.18 no.3
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• pp.321-329
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• 2006

The use of tapered structural members was first proposed by Ami rikian for the economical use of materials.Generaly, tapered members are used in single-story structures with one or more bays and in cantilevered sections of ate architectural representation. If only focused on the section performance, however, the width-to-thickness ratio or t apered ratio can exced regulations. Such a case requires a study on the behavior of tapered members. To investigate the plastic and local buckling behavior of web-tapered beams, seven steel beams were the tapered ratio and the width-to-thicknes ratio. The results of maximum strength, strength deterioration, and stiffnes deterioration were compared.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.165-170
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• 2008

This study discusses the inelastic behavior of single-layer latticed dome, composed of tubular truss member and newly proposed joint sections, through loading test on the scale-down structure. The loading test was performed under displacement control conditions, using loading transfer system for the same value of point loads on all joints. Maximum applied load was nearly 1.6 times of the design load, and inelastic buckling occured beyond compressive yeilding in some members. The displacement of structure was maimtained upto the limit of oil jack. The behavior of latticed dome from the loading test was analyzed on the view of structural design practice.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.1
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• pp.49-56
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• 2011

The strengthening effect of CFRP sheet and AFRP sheet with buckling-restrained brace for Beam-Column joints under constant axial and cyclic lateral loading is evaluated experimentally in this paper. Six test specimens were constructed. The main test parameters included the FRP Sheet and Buckling-restrained braces. The results of the tests were analyzed by focusing on their mode of failure, maximum load, ductility indexes, and energy dissipation capacity. Test results indicated that CFRP Sheet with the buckling-restrained brace system significantly increased the strength and stiffness of the specimen and that it was the most adequate retrofitting method.

• Journal of Korean Society of Steel Construction
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• v.20 no.3
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• pp.437-444
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• 2008

The use of imported structural steel tubes has been increased in domestic construction field because of its low price, but the mechanical properties of those steel tube are not verified exactly. This study includes coupon test and stub - column compression test on the structural steel tube. The compression test of stub - column was performed to characterize and quantify the material characteristic and strength of column compatibility, in which we compared the experiment formula and the abstract formula by the application of the LRFD standard formula and multiple column curve.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.1
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• pp.45-52
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• 2009

The purpose of this study is to evaluate the structural capacities of beam-column specimens retrofitted with CFRP sheet and BRB (Buckling-Restrained Brace) under sustained axial and cyclic lateral loads. Three specimens were made using different retrofitting methods : non-retrofitted, retrofitted with CFRP sheets only, and retrofitted with both CFRP sheet and BRB systems. Lateral load resistant capacities were evaluated based on the load-displacement relations. From the results, the maximum lateral forces of the FRP sheet retrofitted and both the FRP and BRB retrofitted specimens showed approximately 34% and 138% improvement, respectively, compared with the non-retrofitted specimen.