• Structural Engineering and Mechanics
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• 제45권3호
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• pp.277-309
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• 2013

Beam-to-column connections behaviour plays an important role in the analysis and design of steel and precast concrete structures. The paper presents a computer-based method for geometrically nonlinear frames with semi-rigid beam-to-column connections. The analytical procedure employs modified stability functions to model the effect of axial force on the stiffness of members. The member modified stiffness matrix, and the modified fixed end forces for various loads were found. The linear and nonlinear analyses were applied for two planar steel structures. The method is readily implemented on a computer using matrix structural analysis techniques and is applicable for the efficient nonlinear analysis of frameworks.

• 한국강구조학회 논문집
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• 제22권4호
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• pp.313-324
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• 2010

본 연구에서는 반강접 접합부 배치에 따른 구조물 거동특성을 파악하기 위하여 KBC2005 건축구조설계기준으로 비가새 5층 철골 구조물을 설계하여 모든 접합부를 완전 강접합부와 반강접 접합부로 이상화한 경우 그리고 반강접 접합부를 수직배치 및 수평배치한 경우에 대하여 비탄성 시간이력 구조해석을 실시하였다. 철골 보 및 기둥의 모멘트-곡률 관계는 화이버모델을 이용하여 확인하였으며 반강접 접합부의 모멘트-회전각 관계는 3-매개변수 파워모델 그리고 철골 보, 기둥 및 접합부의 이력거동은 3-매개변수 모델을 이용하여 나타내었다. 4개 지진파에 대한 재현주기 2400년 위험수준에 해당하는 최대지반가속도와 5% 층간변위에 대한 푸쉬오버 구조해석의 최대밑면전단력 발생 최대지반가속도에 대하여 시간이력 구조해석을 실시하여 밑면전단력, 지붕층 변위, 층간변위, 접합부 요구연성도, 기둥, 보 및 접합부의 최대휨모멘트 그리고 소성힌지 분포 등을 확인하였다. 반강접 접합부를 수직적으로 외부에 배치할수록 최대밑면전단력과 층간변위는 감소하며, 수평적으로 상부층에 배치할수록 접합부 요구연성도가 감소하였다. 푸쉬오버 구조해석과 시간이력 구조해석에서 최대층간변위 발생 위치가 다르고 크기는 푸쉬오버 구조해석에서 과대평가되었다. 밑면전단력, 층간변위 및 접합부 요구연성도를 위한 가장 바람직한 반강접 접합부 배치는 수직적으로 외부에 배치하는 것이다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.403-410
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• 1999

General1y, H-section is used for columns and beams in the middle and low steel building, But it has a strong and weak axis. Thus if H-section is used for columns, the structure needs reinforcement on the weak axis. Therefore recently, square holler section(S.H.S) is used for columns because it is able to coiler the vulnerability of H-section. Structural analysis is usually executed under the assumption that connections are either ideally pinned joint or fully rigid joint. Actually all connections are semi-rigid which possess a rotational stiffness. Therefore it can be designed economically as using the property of connections which has a rotational stiffness. This paper presents a prediction model curve which is fitted Kishi-Chen power Model about the behavior of connection between H-beam and S.H.S column. Non-linear analysis program was considered the non-linearity of semi-rigid connection and the geometrical non-linearity under the effect of axial force. It was programed by FORTRAN90 and Visual Basic.

• Structural Engineering and Mechanics
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• 제81권2호
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• pp.117-129
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• 2022

This research evaluated the different types of deck to pier connections effects (one or two elastomeric bearing lines and rigid) on a concrete bridges. Three-dimensional bridge models behavior with different deck to pier connections and different distances of two bearing lines were studied under the service load. Also, the detailed connection system with two elastomeric bearing lines was modeled to evaluate the effect of changing distance between two-lines. Results indicated that the proper location of elastomeric bearings has a major impact on the transferring forces to the substructure. Double elastomeric bearing lines have a behavior between one line and rigid connections. Transferring bending moment to the substructure in two-lines is more than the corresponding value of the one line. Moreover, an increase in the distance of two-lines lead to a significant increase in the rotational stiffness of the connection, and an analytical solution was investigated for their relation. In fact, the semi-rigidity effect of this connection and its change due to the distance of bearings should be considered in the design process.

• Steel and Composite Structures
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• 제1권2호
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• pp.213-230
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• 2001

This paper presents a simplified approach for the design of semi-continuous composite beams in braced frames, where specific attention is given to the effect of joint rotational stiffness. A simple composite beam model is proposed incorporating the effects of semi-rigid end connections and the nonprismatic properties of a 'cracked' steel-concrete beam. This beam model is extended to a sub-frame in which the restraining effects from the adjoining members are considered. Parametric studies are performed on several sub-frame models and the results are used to show that it is possible to correlate the amount of moment redistribution of semi-continuous beam within the sub-frame using an equivalent stiffness of the connection. Deflection equations are derived for semi-continuous composite beams subjected to various loading and parametric studies on beam vibrations are conducted. The proposed method may be applied using a simple computer or spreadsheet program.

• 한국강구조학회 논문집
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• 제8권3호통권28호
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• pp.127-137
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• 1996

Connections as basic elements and an integrated part of a steel frame has an effect on the frame's performance. Conventional analysis and design techniques are based on either idealized fixed or pinned conditions. In fact, the use of rigid or pinned connection model in steel frame analysis serves the purpose of simplifying the analysis and design processes, but all connections used in current pratice possess stiffness and transfer moment which fall between the extreme cases of fully rigid and ideally pinned. To predict the behavior of the semi-rigid steel frames, it is necessary to predict the moment-rotation behavior of the beam-to-column connections. In this research, prediction equation for moment-rotation behavior of the beam-to-column connection is suggested and the effect of design parameters has investigated. Prediction model, in a nondimensional form shows the moment-rotation characteristic for connections. It is composed of the curve fitting power function using standardization constant K and 4 parameter $KM_o$, ${\theta}_0$, b, n based on the pretest result about moment-rotation behavior of connection.

• Structural Engineering and Mechanics
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• 제68권5호
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• pp.591-601
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• 2018

Non-moment beam-to-column connections, which are usually referred to as simple or shear connections, are typically designed to carry only gravity loads in the form of vertical shears. Although in the analysis of structures these connections are usually assumed to be pinned, they may provide a small amount of rotational stiffness due to the typical connection details. This paper investigates the effects of this small rotational restraint of simple beam-to-column connections on the behavior and seismic response of steel braced non-moment resisting frames. Two types of commonly used simple connections with bolted angles, i.e., the Double Web angle Connection (DWC) and Unstiffened Seat angle Connection (USC) are considered for this purpose. In addition to the pinned condition - as a simplified representation of these connections - more accurate semi-rigid models are established and then applied to some frame models subjected to nonlinear pushover and nonlinear time history analyses. Although the use of bracing elements generally reduces the sensitivity of the global structural response to the behavior of connections, the obtained results indicate considerable effects on the local responses. Namely, our results show that consideration of the real behavior of connections is essential in designing the column elements where the pin-connection assumption significantly underestimates design of outer columns of upper stories.

• 대한토목학회논문집
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• 제33권2호
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• pp.409-422
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• 2013

부재간의 연결조건에 따른 다양하고 복잡한 강구조물의 P-${\Delta}$ 해석 및 좌굴 거동특성을 파악하기 위하여, 본 연구에서는 부재의 연결이 회전 및 이동스프링으로 구성된 부분강절(semi-rigid) 뼈대요소의 일반화된 접선강도 행렬을 유도하였고 이로부터 다시 Taylor 전개를 적용하여 탄성강도 행렬과 기하학적 강도행렬을 일반화된 형태로 제시하였다. 이를 위하여, 보-기둥부재의 좌굴조건을 만족시키는 처짐함수로부터 안정함수(stability function)를 유도하였고, 횡변위(sway)를 고려한 힘-변위관계와 적합조건을 고려하여 엄밀한 부분강절 뼈대요소의 접선강도행렬을 제시하였다. 다양한 수치해석 예제에 대해 타 연구자의 해석 결과 및 본 연구의 선형 및 비선형 해석이론을 통한 좌굴해석 결과를 비교하여 본 연구의 타당성과 부분강절 뼈대구조물의 좌굴거동 특성을 제시하였다.

• Steel and Composite Structures
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• 제20권5호
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• pp.1155-1171
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• 2016

Post-tensioned (PT) steel moment resisting frames (MRFs) with semi-rigid connections (SRC) can be used to control the hysteretic energy demands and to reduce the maximum inter-story drift (${\gamma}$). In this study the seismic behavior of steel MRFs with PT connections is estimated by incremental nonlinear dynamic analysis in terms of dissipated hysteretic energy ($E_H$) demands. For this aim, five PT steel MRFs are subjected to 30 long duration earthquake ground motions recorded on soft soil sites. To assess the energy dissipated in the frames with PT connections, a new expression is proposed for the hysteretic behavior of semi-rigid connections validated by experimental tests. The performance was estimated not only for the global $E_H$ demands in the steel frames; but also for, the distribution and demands of hysteretic energy in beams, columns and connections considering several levels of deformation. The results show that $E_H$ varies with ${\gamma}$, and that most of $E_H$ is dissipated by the connections. It is observed in all the cases a log-normal distribution of $E_H$ through the building height. The largest demand of $E_H$ occurs between 0.25 and 0.5 of the height. Finally, an equation is proposed to calculate the distribution of $E_H$ in terms of the normalized height of the stories (h/H) and the inter-story drift.

• 한국강구조학회 논문집
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• 제19권5호
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• pp.503-513
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• 2007

구조물의 지진응답은 구조물의 강성도에 영향을 미치는 접합부의 특성에 영향을 받는다. 본 연구에서는 합성반강접 접합부를 갖는 2차원 8층 비가새 철골구조물에 대하여 동적 비선형 해석 프로그램을 이용한 푸쉬오버 해석과 시간이력해석을 실시하여 구조물의 거동을 예측하였다. 접합부 비선형 모멘트-회전 특성, 합성보 및 철골기둥의 재료 비선형 특성을 고려하여 구조해석을 실시하였다. 합성반강접 접합부를 완전 강접합부로 이상화하면 푸쉬오버 해석에서 구조물의 초기강성도와 종국강도가 증가되었고 시간이력해석에서는 밑면전단력, 최대층간변위, 보 및 기둥에 발생되는 최대 휨모멘트가 접합부 강성 및 이력거동의 영향을 받았다. 최대지반가속도가 0.4g인 지진파에 대하여 합성반강접 구조물에서는 FEMA 273의 최대 층간변위에 대한 인명손상방지 기준을 만족하였으며 보와 기둥이 비탄성 거동을 경험하지 않은 반면 완전 강접합부로 이상화한 구조물에서는 보 및 기둥이 비탄성 거동을 경험하였다.