• Title/Summary/Keyword: coupling beams

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Seismic Performance of Coupled Shear Wall Structural System with Relaxed Reinforcement Details (완화된 배근 상세를 갖는 병렬전단벽 구조시스템의 내진성능평가)

  • Song, Jeong-Weon;Chun, Young-Soo;Song, Jin-Kyu;Seo, Soo-Yeon;Yang, Keun-Hyeok
    • Journal of the Korea Concrete Institute
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    • v.28 no.2
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    • pp.187-196
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    • 2016
  • The current seismic design code prescribes that coupling beam should be reinforced using diagonally bundled bars. However, the use of a diagonally bundled bars has a negative effect on constructability and economic efficiency. In the present study, the seismic performance of 4 coupling beams with the different details of reinforcement was evaluated through a cyclic reversal loading test. The specimens were constructed to measure the results of the experimental variable regarding the details of shear reinforcement. Next, the seismic performance of the coupled shear wall system evaluated by methods proposed in the FEMA P695. The cyclic reversal loading test results of this study showed that the performance of coupling beams with relaxed reinforcement detail was almost similar to that of a coupling beam with the ACI detail and meet the level which requested from standard. The result of the seismic evaluation showed that all coupling beams are satisfied with the design code and seismic performance.

Vibration Analysis of Rotating Cantilever Beams Considering the Elastic Foundation Effect (지지부 탄성효과를 고려한 회전 외팔 보의 진동해석)

  • 윤경재;유홍희
    • Journal of KSNVE
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    • v.10 no.6
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    • pp.1022-1028
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    • 2000
  • This paper presents a modeling method for the vibration analysis of rotating cantilever beams considering the elastic foundation effect. Mass and stiffness matrices are derided explicitly by considering coupling effect between stretching and bonding motion. Numerical results show that the bending direction elastic foundation stiffness influences the vibration characteristics significantly in practical range of beam configuration. The ranges of elastic foundation stiffness to avoid the dynamic buckling are also presented. The method presented in this paper can be used to predict the variations of natural frequencies of rotating cantilever beams with elastically restrained root.

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Experimental Study of Spatial and Temporal Dynamics in Double Phase Conjugation

  • Kwak, Keum-Cheol;Yu, Yong-Hun;Lim, Tong-Kun;Lee, Dae-Eun;Son, Jung-Young
    • Journal of the Optical Society of Korea
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    • v.3 no.2
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    • pp.41-46
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    • 1999
  • Spatial and temporal dynamics arising in a photorefractive crystal(BaTiO3) during the process of double phase conjugation was studied experimentally. We studied the dynamical effects caused by the buildup of the diffraction grating and turn on of phase conjugated beams, as well as the spatial effects caused by the finite transverse coupling of beams and the propagation direction of beams. We observed conical emission in DPCM. We believe that various temporal and spatial instabilities are due to movement of the nonlinear grating. For a real beam coupling and constructive interaction of interference fringes in the crystal, we observed steady, periodic, irregular temporal behavior. And, by the calculation of the correlation index, we found that the spatial correlation decreased as the transverse interaction region was increased.

Performance based evaluation of RC coupled shear wall system with steel coupling beam

  • Bengar, Habib Akbarzadeh;Aski, Roja Mohammadalipour
    • Steel and Composite Structures
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    • v.20 no.2
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    • pp.337-355
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    • 2016
  • Steel coupling beam in reinforced concrete (RC) coupled shear wall system is a proper substitute for deep concrete coupling beam. Previous studies have shown that RC coupled walls with steel or concrete coupling beam designed with strength-based design approach, may not guarantee a ductile behavior of a coupled shear wall system. Therefore, seismic performance evaluation of RC coupled shear wall with steel or concrete coupling beam designed based on a strength-based design approach is essential. In this paper first, buildings with 7, 14 and 21 stories containing RC coupled shear wall system with concrete and steel coupling beams were designed with strength-based design approach, then performance level of these buildings were evaluated under two spectrum; Design Basis Earthquake (DBE) and Maximum Considered Earthquake (MCE). The performance level of LS and CP of all buildings were satisfied under DBE and MCE respectively. In spite of the steel coupling beam, concrete coupling beam in RC coupled shear wall acts like a fuse under strong ground motion.

Evaluation of Seismic Performance of Bearing Wall Structure with Coupling Beam (연결보가 있는 벽식 구조물의 내진성능 평가)

  • Lee, Young-Wook;Tao, Zou
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.1049-1052
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    • 2008
  • Coupling beams have been used in bearing wall system during last decades. Practically their sectional effects are fully considered in analysis stage to control lateral displacement because they have good contribution to the stiffness of bearing wall system. But the high resultant forces of coupling beam are not fully satisfied in design stage because coupling beams are restricted in sectional size. In this paper the performance of bearing wall system with coupling beam has been evaluated based on improved equivalent linearization procedure of FEMA 440. 15 storied building is selected for analysis. Variables for performance evaluation are natural period, degree of coupling and soil site. To evaluate performance, demand capacity spectrum is calculated based on KBC 2005. As a result, for the most of the cases the life safety limit of chord rotation of coupling beam is less than the performance point of system for soil site $S_D$. That means that the coupling beam can be severly damaged before the system reaches at performance point.

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Seismic behavior of coupled wall structure with innovative quickly replaceable coupling beams

  • Li, Yong;Yu, Haifeng;Liang, Xiaoyong;Yu, Jianjun;Li, Pengcheng;Wang, Wei;Wang, Qizhi
    • Steel and Composite Structures
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    • v.45 no.2
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    • pp.293-303
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    • 2022
  • In order to improve the seismic resilience of coupled wall structure, coupling beam with fuse has been developed to reduce the post-earthquake damage. However, the fuses often have a build-up I-shaped section and are relatively heavy to be replaced. Moreover, the fuse and the beam segments are usually connected by bolts and it is time-consuming to replace the damaged fuse. For reducing the repair time and cost, a novel quickly replaceable coupling beam with buckling-restrained energy dissipaters is developed. The fuse of the proposed coupling beam consists of two chord members and bar-typed energy dissipaters placed at the corners of the fuse. In this way, the weight of the energy dissipater can be greatly reduced. The energy dissipaters and the chords are connected with hinge and it is convenient to take down the damaged energy dissipater. The influence of ratio of the length of coupling beam to the length of fuse on the seismic performance of the structure is also studied. The seismic performance of the coupled wall system with the proposed coupling beam is compared with the system with reinforced concrete coupling beams. Results indicated that the weight and post-earthquake repair cost of the proposed fuse can be reduced compared with the typical I-shaped fuse. With the increase of the ratio of the beam length to the fuse length, the interstory drift of the structure is reduced while the residual fuse chord rotation is increased.

The Effects of Coupling Beam on Lateral Drift of High-rise Buildings (고층건물의 횡변위에 대한 커플링보의 효과)

  • Kim, Jin-Sang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.12
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    • pp.5931-5937
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    • 2011
  • The effects of coupling beam, which is generally used in high-rise building structure system as shear wall-coupling beam, on the lateral drift of high-rise buildings are studied in this paper. Six different analytical models, which are combination of two inputs, such as concrete strength and wall thickness, are selected and analyzed on lateral drifts with different stiffness of coupling beams. MIDAS GEN was used for analysis. Calculated lateral drifts were compared with allowable limits(H/400~H/500) proposed by standard CEN EC 3/1, in order to analyze the control evaluation of coupling beams. Calculated x-direction displacements were 68~87 percent of allowable limit(H/500). With increase of wall thickness(100mm) and concrete strength(5Mpa), eight to ten percent and four percent of x and y-direction displacement were decreased individually. About three percent of lateral displacement was increased with 20 percent decrease of coupling beam stiffness and additional 20 percent decrease resulted in additional five to eight percent increase.

Seismic Performance Evaluation of Staggered Wall Structures Using FEMA P695 (FEMA P695를 이용한 격간벽 구조의 내진성능평가)

  • Lee, Joon-Ho;Kang, Hyun-Goo;Lee, Min-Hee;Kim, Jin-Koo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.3
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    • pp.43-50
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    • 2012
  • The FEMA P695 document proposed a methodology to evaluate the collapse safety of a structure and the validity of the seismic design coefficients. In this study, the seismic performance of six- and twelve-story staggered wall structures with a middle corridor was evaluated based on the FEMA P695 procedure. The analysis results of the prototype structures were compared with those of the structures with an increased coupling beam depth or an increased re-bar ratio of the coupling beams in order to investigate the effect of retrofit. The adjusted collapse margin ratios (ACMR) of the model structures obtained from incremental dynamic analyses turned out to be larger than the specified limit states of an ACMR of 20%, which implies that the analysis model structures have enough strength against design level earthquakes. It was also observed that the increase in the re-bar ratio of the coupling beams between the staggered walls was more effective in increasing the ACMR than an increase in the depth of the coupling beams.

Seismic Performance Evaluations of RC Bearing Wall Systems with Coupling Beams - For Apartment Buildings in 1990s (연결보가 있는 철근콘크리트 내력벽시스템의 내진성능평가 -1990년대 공동주택을 중심으로-)

  • Lee, Young-Wook;Chae, J.-Yong
    • Journal of the Earthquake Engineering Society of Korea
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    • v.15 no.4
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    • pp.23-31
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    • 2011
  • To investigate the performance of apartment buildings which were built in the 1990s and which have RC bearing wall systems with coupling beams, construction drawings of 13 buildings were collected and analyzed. To evaluate the seismic performance, FEMA 356 and FEMA 440 were selected as guidelines. For the demand curve, the seismic design spectrum in KBC 2009 is used. For each building, the performance points for life safety and the collapse prevention state are calculated. It was found that 9 out of 13 buildings (about 70%) showed damage more severe than the collapse prevention level at the performance point and more damage could be seen at the coupling beams than the walls. However, the story drift limit of FEMA 356 was satisfied for all buildings. Through the analysis of performance points, it was shown that the spectral acceleration has an inverse relationship with the natural period.

Structural Performance of Hybrid Coupled Shear Wall System Considering Connection Details (접합부 상세에 따른 복합 병렬 전단벽 시스템의 구조 성능)

  • Park, Wan Shin;Yun, Hyun Do;Kim, Sun Woong;Jang, Young Il
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.3
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    • pp.128-137
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    • 2012
  • In high multistory buildings, hybrid coupled shear walls can provide an efficient structural system to resist horizontal force due to wind and seismic loads. Hybrid coupled shear walls are usually built over the whole height of the building and are laid out either as a series of walls coupled by steel beams with openings to accommodate doors, elevator walls, windows and corridors. In this paper, the behavior characteristics of hybrid coupled shear wall system considering connection details is examined through results of an experimental research program where 5 two-thirds scale specimens were tested under cyclic loading. Such connections details are typically employed in hybrid coupling wall system consisting of steel coupling beams and reinforced concrete shear wall. The test variables of this study are embedment length of steel coupling beam and wall thickness of concrete shear wall. The results and discussion presented in this paper provide fundamental data for seismic behavior of hybrid coupled shear wall systems.