• Title/Summary/Keyword: rigid frame

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Improvement and Evaluation of Structural performance of Reinforced Concrete Infilled Masonry Frame with Restraining Factor of Frame under Load Reversals (반복하중을 받는 철근콘크리트 프레임면내 조적벽체의 골조 구속에 따른 구조성능 평가 및 개선)

  • 신종학;하기주;김광연;이희종;남왕교
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.541-546
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    • 2001
  • Experimental programs were accomplished to improve and evaluate the structural performance of test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation of and ductility etc. Test variables are restraining factors of frame, with or without masonry infilled wall, and masonry method Six reinforced concrete rigid frame and masonry infilled wall were tested and constructed in one-third scale size under vertical and cyclic loads simultaneously. Based on the test results, the following conclusions can be made. For masonry infilled wall with restraining factors of frame, maximum horizontal capacities were increased by 1.91~2.24 times in comparision with that of rigid frame. For masonry infilled wall with restraining factors of frame(IFWB-l~3), cumulated energy dissipation capacities wear increased by 1.35~l.60 times in comparision with that of masonry infilled wall(IFB-1) at final stage of testing.

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Serviceability design of a cold-formed steel portal frame having semi-rigid joints

  • Lim, J.B.P.;Nethercot, D.A.
    • Steel and Composite Structures
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    • v.3 no.6
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    • pp.451-474
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    • 2003
  • Details are given of a cold-formed steel portal framing system that uses simple bolted moment-connections for both the eaves and apex joints. However, such joints function as semi-rigid and, as a result, the design of the proposed system will be dominated by serviceability requirements. While serviceability is a mandatory design requirement, actual deflection limits for portal frames are not prescribed in many of the national standards. In this paper, a review of the design constraints that have an effect on deflection limits is discussed, and rational values appropriate for use with cold-formed steel portal frames are recommended. Adopting these deflection limits, it is shown through a design example how a cold-formed steel portal frame having semi-rigid eaves and apex joints can be a feasible alternative to rigid-jointed frames in appropriate circumstances.

Stability analysis of semi-rigid composite frames

  • Wang, Jing-Feng;Li, Guo-Qiang
    • Steel and Composite Structures
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    • v.7 no.2
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    • pp.119-133
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    • 2007
  • Based on stability theory of current rigid steel frames and using the three-column subassemblage model, the governing equations for determining the effective length factor (${\mu}$-factor) of the columns in semirigid composite frames are derived. The effects of the nonlinear moment-rotation characteristics of beam-to-column connections and composite action of slab are considered. Furthermore, using a two-bay three-storey composite frame with semi-rigid connections as an example, the effects of the non-linear moment-rotation characteristics of connections and load value on the ${\mu}$-factor are numerically studied and the ${\mu}$-factors obtained by the proposed method and Baraket-Chen's method are compared with those obtained by the exact finite element method. It was found that the proposed method has good accuracy and can be used in stability analysis of semi-rigid composite frames.

Development of the Nonlinear Structural Analysis Model for the Light-Weight Framed Structures (II) (경량형강 시설물의 비선형 구조해석 모델개발(II) -반강결 뼈대구조물의 해석에 대하여-)

  • 김한중;이정재
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.1
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    • pp.78-87
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    • 1998
  • In this study, semi-rigid light-weight framed structures analysis model (SERIFS) was developed by advancing the LEIFS model. This model enables us to analyze simultaneous effects of large deflection and semi-rigid connection by computing unbalanced load occurring in the process of repeated loading through equalization of bending moments and torsion. This model is also able to handle the effect of the semi-rigid connection and large deflection by modifying the elastic stiffness matrix using moment-rotation behavior of connection. Moment-rotation behavior of the semi-rigid connection was adopted from the experimental results of load-vertical displacement of frame element In conclusion, this model achieves to analyze the nonlinear and large deflection behavior on the semi-rigid and light-weight steel frame connection.

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Inelastic Buckling Analysis of Semi-rigid Frames with Shear Deformations by Haringx's Theories (Haringx의 전단변형 이론을 고려한 부분강절 뼈대구조의 비탄성 좌굴해석)

  • Min, Byoung-Cheol
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.64-71
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    • 2014
  • The generalized tangential stiffness matrix of semi-rigid frame element with shear deformations based on Haringx's shear theory is newly derived and compared with the previous study based on Engesser's shear theory. Also, linearized elastic and geometric stiffness matrices are newly presented from the exact tangential stiffness matrix. In oder to obtain the inelastic system buckling load of shear flexible semi-rigid frame structure, the Ef method by tangential modulus theory is adopted and the FE analysis programs are developed. Finally, the shear and semi-rigid effects of system bucking are investigated by two numerical examples.

Dynamic Analysis of Superstructures on Very Large Floating Structure with Semi-Rigid Connections (반강접 접합부를 적용한 초대형 부유식 구조물 상부구조체에 대한 동적해석)

  • Song Hwa-Cheol;Kim Woo-Nyon
    • Journal of Navigation and Port Research
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    • v.29 no.5 s.101
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    • pp.389-394
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    • 2005
  • The additional moment occurs because the superstructures of VLFS are influenced by wave loads instead of earthquake loads. In order to reduce the additional moment, this study used the semi-rigid connections which lie between fully rigid and pinned. If the semi-rigid connections are used for superstructures of VLFS, the moment of beams can be reduced and more economical construction will be possible. This study aims to show the effect of wave loads on structure and the efficiency of the semi-rigid connections due to wave loads by analyzing the time history responses. The dynamic behaviors of the rigid frame are compared with those of the semi-rigid frame considering of static loads, wave loads and combination loads for a four-bay, three-story frames. The semi-rigid connection type is a steel tubular column with square external-diaphragm connections and the time history analysis is used for the dynamic responses. The additional moment responses due to wave loads increase $33\%$ in the rigid frame, $26\%$ in the semi-rigid frame with the spring model.

Development of Technique for Improvement of Earthquake-Resistant Performance of Reinforced Concrete Infilled Masonry Frame (철근콘크리트 프레임면내 조적벽체의 내진성능개선 기술 개발)

  • 신종학;하기주;최민권;권중배;남왕교
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.1143-1148
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    • 2001
  • Experimental programs were accomplished to improve and evaluate the structural performance of test specimens, such as hysteretic behavior, maximum horizontal strength, crack propagation, and ductility etc. Test variables are restraining factors of frame, with or without masonry infilled wall, and masonry method. Six reinforced concrete rigid frame and masonry infiiled wall were constructed and tested in one-third scale size under vertical and cyclic loads simultaneously. Based on the test results, the following conclusions can be made. For masonry infilled walls with restraining factors of frame, maximum horizontal capacities were increased by 1.26~2.24 times in comparision with that of rigid frame. For masonry infilled wall with restraining factors of frame(IFWB-1), cumulated energy dissipation capacities wear increased by 1.60 times in comparision with that of masonry infilled wall(IFB-1) at final stage of testing.

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Improvement and Evaluation of Seismic Resistant Performance of Reinforced Concrete Infilled Masonry Frame (철근콘크리트 프레임면내 조적벽체의 내진성능 평가 및 개선기술)

  • Shin, Jong-Hack;Ha, Gee-Joo;Jun, Ha-Suk;Lee, Jong-Chan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.4 no.1
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    • pp.147-155
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    • 2000
  • Five reinforced concrete rigid frame and masonry infilled wall and cut off type masonry infilled wall were tesed during vertical and cyclic loads simultaneously. Experimental programs were accomplished to improve and evaluate the structural performance of test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. Test variables are hoop reinforcement ratio, with or without masonry infilled wall, and masonry method. All the specimens were constructed in one-third scale size. Based on the test results, the following conclusions can be made. For masonry infilled wall(IFB-1), maximum horizontal capacity was increased by 1.45 time in comparision with that of rigid frame(FB-0). For cut off masonry infilled wall (IFBC-1~3), maximum horizontal capacity was increased by 1.73~1.98 time in comparision with that of rigid frame(FB-0). For cut off masonry infilled wall(IFBG-1~3), ductility was increased by 1.48~2.08 time in comparision with that of masonry infilled wall (IFB-1).

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Evaluation of Moment Resistance of Rigid Frame with Glued Joint (강절형 목질접합부의 모멘트저항성능 평가)

  • Lee, In-Hwan;Song, Yo-Jin;Hong, Soon-Il
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.1
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    • pp.28-35
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    • 2017
  • In this study, specimens of rigid frame joint were produced by integrating joints with adhesive and other specimens were produced by inserting a wooden gusset integrated with a column member into a slit-processed beam member and joining them with pins. Then the moment resistance performances of the specimens were examined. For the wooden gusset, a GFRP-reinforced wooden gusset was used. The calculation results of perfect elasto-plasticity for the frame specimens for which a GFRP-reinforced wooden gusset was inserted into and joined with the slit-processed beam member by pins were 20-80% lower compared to the control group which consisted of steel plate-inserted frame specimens. The rigid frame specimens for which the column and beam members have been integrated with adhesive showed almost no initial residual transformations, as well as 38% greater initial rigidity and 41% greater plasticity compared to the steel plate-inserted joint.

Influence of joint modelling on the pushover analysis of a RC frame

  • Costa, Ricardo;Providencia, Paulo;Ferreira, Miguel
    • Structural Engineering and Mechanics
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    • v.64 no.5
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    • pp.641-652
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    • 2017
  • In general, conventional analysis and design of reinforced concrete (RC) frame structures overlook the role of beam-column (RCBC) joints. Nowadays, the rigid joint model is one of the most common for RCBC joints: the joint is assumed to be rigid (unable to deform) and stronger than the adjacent beams and columns (does not fail before them). This model is popular because (i) the application of the capacity design principles excludes the possibility of the joint failing before the adjacent beams and (ii) many believe that the actual behaviour of RCBC joints designed according to the seismic codes produced mainly after the 1980s can be assumed to be nominally rigid. This study investigates the relevance of the deformation of RCBC joints in a standard pushover analysis at several levels: frame, storey, element and cross-section. Accordingly, a RC frame designed according to preliminary versions of EN 1992-1-1 and EN 1998-1 was analysed, considering the nonlinear behaviour of beams and columns by means of a standard sectional fibre model. Two alternative models were used for the RCBC joints: the rigid model and an explicit component based nonlinear model. The effect of RCBC joints modelling was found to be twofold: (i) the flexibility of the joints substantially increases the frame lateral deformation for a given load (30 to 50%), and (ii) in terms of seismic performance, it was found that joint flexibility (ii-1) appears to have a minor effect on the force and displacement corresponding to the performance point (seismic demand assessed at frame level), but (ii-2) has a major influence on the seismic demand when assessed at storey, element and cross-section levels.