• Title/Summary/Keyword: X-브레이싱

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Out-of-Plane Effective Length Factor of X-Bracing System (X-브레이싱의 면외 유효 좌굴길이 계수)

  • Moon, Ji Ho;Yoon, Ki Yong;Lee, Hak Eun
    • Journal of Korean Society of Steel Construction
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    • v.19 no.1
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    • pp.129-137
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    • 2007
  • In this study, the elastic out-of-plane buckling load and the effective length factor of X-bracing systems were studied. Points of the intersection of diagonals were modeled as a rigid connection or a pinned connection depending on the connection method of diagonals. The boundary condition of the intersection influences the buckling load of X-bracing systems. For each boundary condition of the intersection, effective out-of-plane length factors of X-bracing systems were derived as a function of the length ratio of tension and compression diagonals $L_P$/$L_T$, the applied force ratio of tension and compression diagonals T/P, and the Euler buckling load ratio of tension and compression diagonals $P_{ET}$/$P_{EP}$. The proposed effective out-of-plane length factors of X-bracing systems were compared with the results of previous researchers and those of the finite element analysis and their properties were verified. Finally, the effects of the boundary condition of the intersection on the out-of-plane buckling load of X-bracing systems were investigated.

Evaluation of Seismic Performance on Shear Walls in Steel House (스틸하우스 전단벽체의 내진성능평가)

  • 이재석;이승은;홍건호;김원기
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.6
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    • pp.65-72
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    • 2002
  • This study estimates steel house shear wall's seismic performance depending on trend of seismic design. As a result at cyclic-test, the capability of energy dissipation about X1SPCH during this test is good enough. The capability of energy dissipation of X3SPCH and X4SPCH was better than that of X1SPCH. The X2SPCH which is similar to real X-braced shear wall has better seismic performance than shear wall braced with structural sheathing materials on pseudo-dynamic test.

Seismic Strengthening and Performance Evaluation of Damaged R/C Buildings Strengthened with Glass Fiber Sheet and Carbon Fiber X-Brace System (GFS-CFXB 내진보강법을 이용한 지진피해를 받은 R/C 건물의 내진성능 평가 및 내진보강 효과)

  • Lee, Kang-Seok
    • Journal of the Korea Concrete Institute
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    • v.25 no.6
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    • pp.667-674
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    • 2013
  • Improving the earthquake resistance of buildings through seismic retrofitting using steel braces can result in brittle failure at the connection between the brace and the building, as well as buckling failure of the braces. This paper proposes a new seismic retrofit methodology combined with glass fiber sheet (GFS) and non-compression X-brace system using carbon fiber (CFXB) for reinforced concrete buildings damaged in earthquakes. The GFS is used to improve the ductility of columns damaged in earthquake. The CFXB consists of carbon fiber bracing and anchors, to replace the conventional steel bracing and bolt connection. This paper reports the seismic resistance of a reinforced concrete frame strengthened using the GFS-CFXB system. Cyclic loading tests were carried out, and the hysteresis of the lateral load-drift relations as well as ductility capacities were investigated. Carbon fiber is less rigid than the conventional materials used for seismic retrofitting, resulting in some significant advantages: the strength of the structure increased markedly with the use of CF X-bracing, and no buckling failure of the bracing was observed.

Retrofitting Effects and Structural Behavior of RC Columns Strengthened with X-Bracing Using Carbon Fiber Anchor (탄소섬유 앵커 X-브레이싱으로 보강된 철근콘크리트 기둥의 구조거동 및 내진보강 효과)

  • Sim, Jong-Sung;Lee, Kang-Seok;Kwon, Hyuck-Woo;Kim, Hyun-Joong
    • Journal of the Korea Concrete Institute
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    • v.24 no.3
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    • pp.323-331
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    • 2012
  • This paper presents a new strengthening method on concrete column against seismic loads for structural performance tests. An X-bracing using high performance carbon fiber threads called the "Carbon fiber anchor X-bracing system" is used to connect RC frames internally. The carbon fiber sheet is wrapped around the column to fix the top and bottom of the column after Super anchor was installed by drilling hole on the column. The structural performance was evaluated experimentally and analytically. Two types of columns specimens were made; flexure fracture scaled model and shear fracture scaled model. For the performance evaluation, cyclic loading tests were conducted on moment and shear resisting columns with and without X bracing. Test results confirmed that the bracing system installed on RC columns enhanced the strength capacity and provided adequate ductility.

A Development of Seismic Rehabilitation Method of RC Buildings Strengthened with X-Bracing Using Carbon Fiber Composite Cable (X-가새형 탄소섬유케이블을 이용한 중·저층 철근콘크리트 건물의 내진보강법 개발)

  • Lee, Kang-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.3
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    • pp.1-9
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    • 2014
  • Improving the earthquake resistance of buildings through seismic retrofitting using steel braces can result in brittle failure at the connection between the brace and the building, as well as buckling failure of the braces. In this study, a non-compression cross-bracing system using the Carbon Fiber Composite Cable (CFCC), which consists of CFCC bracing and bolt connection was proposed to replace the conventional steel bracing. This paper presented the seismic resistance of a reinforced concrete frame strengthened using CFCC X-bracing. Cyclic loading tests were carried out, and the maximum load carrying capacity and ductility were investigated, together with hysteresis of the lateral load-drift relations. Test results revealed that the CFCC X-bracing system installed RC frames enhanced markedly the strength capacity and no buckling failure of the bracing was observed.

Experimental Study on the Presentation of Adequate Type and Number of Bracing Panel for Design of U-Shaped Steel Box Girder (U형 강박스거더의 휨설계를 위한 합리적인 브레이싱의 형태 및 패널 수 도출에 관한 실험적 연구)

  • Shim, Nak-Hoon;Park, Young-Suk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.1
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    • pp.68-76
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    • 2007
  • In the present study, tests for U-type steel box girder are performed to observe the effects of W-type and X-type of top lateral bracings on the bending behavior of the U-type steel box girder system. Another objective of the present study is to investigate the adequacy of the currently available design formula. For the structural tests, the test specimen with two third scale of the system constructed in the field was used. In this test, several different spacings are used for the top lateral bracings. The stresses measured from the bending tests are compared with those by the formula proposed by Helwig. An adequate type and the required number of panel for diagonal bracing was obtained.

A Study on the Analysis of Steel Bracing Behaviour Subjected to Cyclic Loads (반복하중을 받는 강재 브레이싱의 거동에 관한 해석적 연구)

  • 구민세;김병석;김일곤
    • Computational Structural Engineering
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    • v.2 no.3
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    • pp.69-75
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    • 1989
  • The primary purpose of using bracings is to improve the lateral rigidity of main structural system, i.e., columns and beams, by reinforciing them with much smaller members. In conventional design methods brackings are considered as tension-only members, since difficulties arise in the analysis when the P-.DELTA. effects and post-buckling behaviour of the bracing members are taken into account. This is particulary true fox X-bracings. Recently, however, both analytical and experimental studies have been conducted to investigate the more precise and real behaviour of bracing members, especially for the nonlinear and plastic behaviour under cyclic loads. In this study, an analytical model is proposed to investigate the nonlinear behavior of steel bracing members subjected to cyclic loads. Results of the analysis were compared with previous experimental results, and good agreements were obtained between these results.

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Out-of-Plane Elastic Buckling of X-Bracing System with Fixed Ends (고정 지점을 갖는 X-브레이싱의 탄성 면외 좌굴)

  • Moon, Ji-Ho;Yoon, Ky-Yong;Lee, Hak-Eun
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.293-296
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    • 2007
  • This study investigated the out-of-plane elastic buckling load and effective length factor of X-bracing system. The members of X-bracing system which are studied in this paper are rigidly attached to the structure at their end connections, and are pinned or rigidly connected at their point of intersection. The effective length factors are derived for the general case where the tension and compression brace have different material and geometrical properties.

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A Study on the Analysis of Steel Bracing Behaviour Subjected to Cyclic loads (반복하중을 받는 강재 브레이싱의 거동에 관한 해석적 연구)

  • 구민세;김병석;김일곤
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1989.04a
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    • pp.44-49
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    • 1989
  • The primary purpose of using bracings is to improve tile lateral rigidity of main structural system, i.e., columns and beams, by reinforcing them with much smaller members. Conventional design methods consider bracings as tension-only mambers, since difficulties arise in the analysis to consider the P - effects and post-buckling behaviour of the bracing members. This is particulary true for X-bracings. Recently, however, both analytical and experimental studies have been conducted to investigate the more precise and real behaviour of bracing members, especially for the nonlinear un plastic behaviour under cyclic loads. In this study, an analytical model is proposed to investigate the nonlinear behavior of steel bracing members subjected to cyclic loads. Results of tile analysis were compared with previous experimental results, and good agreements were obtained between these results.

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A study on vibration control of the engine body for a large scale diesel engine using the semi-active controlled hydraulic type of top bracing (준능동형 유압식 톱브레이싱을 이용한 선박용 저속 2행정 디젤엔진의 본체 진동제어)

  • Lee, Moon-Seek;Kim, Yang-Gon;Hwang, Sang-Jae;Lee, Don-Chool;Kim, Ue-Kan
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.6
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    • pp.632-638
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    • 2014
  • Nowadays, as part of an effort to increase the efficiency of propulsion shafting system, the revolution of the main diesel engine in CMCR(Contract Maximum Continuous Rating) is reduced whereas the stiffness of hull structure supporting the main diesel engine is relatively flexible. However, vibration problems related with resonant response of main diesel engine are increasing although top bracing is installed between the main diesel engine and the hull structures to increase natural frequency of engine body above CMCR to avoid resonant phenomenon. In this study, the dynamic characteristic of top bracing is reviewed by analyzing measuring results of general cargo ships which apply the hydraulic type instead of the friction type to control the natural frequency and the vibration of the engine body. Moreover, considering the vibration characteristic of the engine body and the hydraulic type of the top bracing by varying the number of top bracing, authors suggest the more effective way to control the vibration of the engine body despite of lower stiffness of the hull structure than in the past when the hydraulic type of top bracing is used.