• Structural Engineering and Mechanics
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• 제75권2호
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• pp.211-227
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• 2020

The contribution of infill wall is generally not considered in the structural analysis of reinforced concrete (RC) structures due to the lack of knowledge of the complex behavior of the infilled frame of RC structures. However, one of the significant factors affecting structural behavior and earthquake performance of RC structures is the infill wall. Considering structural and architectural features of RC structures, any infill wall may have openings with different amounts and aspect ratios. In the present study, the influence of infill walls with different opening rates on the structural behaviors and earthquake performance of existing RC structures were evaluated. Therefore, the change in the opening ratio in the infill wall has been investigated for monitoring the change in structural behavior and performance of the RC structures. The earthquake performance levels of existing RC structures with different structural properties were determined by detecting the damage levels of load-carrying components. The results of the analyzes indicate that the infill wall can completely change the distribution of column and beam damage level. It was observed that the openings in the walls had serious impact on the parameters affecting the behavior and earthquake performance of the RC structures. The infill walls have a beneficial effect on the earthquake performance of RC structures, provided they are placed regularly and there are appropriate openings rate throughout the RC structures and they do not cause structural irregularities.

• Steel and Composite Structures
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• 제27권4호
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• pp.401-416
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• 2018

Composite beams with web openings are vulnerable to Vierendeel bending failure. The available methods provide quite conservative estimates of Vierendeel bending resistance. An alternative design method to compute the resistance was proposed in this study, based on quadratic nonlinear interactions of normalized shear force, axial force and Vierendeel bending moment. The interactions of the top and bottom Tee section must satisfy mutual conditions to prevent the Vierendeel failure. The normalized shear force and Vierendeel bending moment of the composite part were used instead in the top Tee interaction. The top Tee axial force was computed based on force equilibrium. Based on a rigid-plastic model, the composite resistance is estimated using an effective slab width of the vertical shear resistance. On using the proposed method, nonlinear reductions due to shear loads and axial forces are not required, in contrast to prior methods. The proposed method was validated against experiments from literature. The method limitations and accuracy as well as the Vierendeel behavior were investigated by finite element simulations, with varied composite beam parameters. The proposed design loads are less conservative than earlier estimates and deviate less from the simulations.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.701-706
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• 2001

This study is aimed to investigate on the structural properties(like as strength, failure mode, ductility) of beams with multiple openings reinforced with steel tube of circular. The main parameters are follows ;1)location of openings, 2)the number of opening, 3) existence of opening or not. When the locations of opening are respectively maximal moment zone, maximal shear zone, co-existence zone of moment and shear, the specimen with opening at maximal moment zone is not less than that without opening in terms of strength and ductility. The specimens with opening at shear zone and both zones are expected to carry the structural performance corresponding to beam without opening by varying the number and reinforcing method of opening.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.135-140
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• 1998

The buckling of the perforated web of a simply supported Η-section beam subjected to uniformly distributed load is examined by means of the finite element method. With buckling analysis results, the effect of this hole on the load carrying capacity of the beam with dimensions L/h = 11 and 13 ( L = span length h = web depth) is investigated. The parameters whose variation have been considered are hole size and location. It can be generally concluded that the buckling of the perforated web of an H-section beam is not affected seriously by the location of the perforation.

• 한국강구조학회 논문집
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• 제12권5호통권48호
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• pp.595-604
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• 2000

유공합성보는 공기조화설비등의 각종 배관으로 인한 용적률의 저하를 완화할 수 있고, 바람과 같은 수평력에 의한 층모멘트 감소등의 구조적 측면에서도 유용하다. 또한 휨강성도 증가되어 하중에 의한 처짐이 적어지고 진동하중이나 충격하중에도 유리하게 되어 건축물의 강성 및 내력을 높이기 위해 사용되고 있다. 그러나 개구부 위치 및 편심여부에 따라 외력에 대한 구조적인 거동이 달라지게 되므로 이에 대한 적절한 검토가 요구된다. 이에 본 논문은 편심유공합성보의 종국내력 및 변형능력에 관한 실험적 연구로서, 무공합성보인 기준시험체와 중심 및 상 하 편심유공합성보 시험체의 실험 및 이론적 고찰을 통하여 각 시험체들의 항복 및 최대내력, 휨 및 전단강성, 개구부주위의 응력분포, 그리고 모멘트-전단력 상관관계등의 구조적 특성을 규명코자 한다.

• 한국전산구조공학회논문집
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• 제28권6호
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• pp.667-674
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• 2015

본 논문은 유공형 판 형태로 전단보강한 넓은 보의 전단파괴 실험을 수행하여 넓은 보의 거동을 평가하였다. 무보강 시험체, 유공형 강판으로 전단보강된 시험체 5개와 유공형 GFRP로 보강된 시험체 5개 총 11개의 시험체를 전단파괴 실험을 통해 계측한 전단강도와 ACI-318 규준의 설계식을 통해 얻은 전단강도와 비교 평가하였다. 또한 넓은 보의 전단보강재의 재료, 종방향 전단보강재의 간격과 횡방향 전단보강재의 간격을 변수로 하여 넓은 보의 거동과 전단강도에 미치는 영향을 분석하였다. 이를 통해 종방향과 횡방향 전단보강재 간격이 줄어들수록 전단강도가 증가하고 사인장 균열이 적게 발생하는 것을 확인하였다. 또한 전단보강재의 재료인 강재와 GFRP에 상관없이 전단보강량이 동일하다면 넓은 보에서 비슷한 전단보강효과를 보이는 것을 확인하였다.

• Steel and Composite Structures
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• 제22권1호
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• pp.183-201
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• 2016

Perforated steel beams can be optimised by increased beam depth and the moment of inertia combined with a reduced web thickness, favouring the use of original I-section beams. The designers are often confronted with situations where optimisation cannot be carried out effectively, taking account of the buckling risk at web posts, moment-shear transfers and local plastic deformations on the transverse holes of the openings. The purpose of this study is to suggest solutions for reducing these failure risks of tested optimal designed beams under applying loads in a self-reacting frame. The design method for the beams is the hunting search optimisation technique, and the design constraints are implemented from BS 5950 provisions. Therefore, I have aimed to explore the strengthening effects of reinforced openings with ring stiffeners, welded vertical simple plates on the web posts and horizontal plates around the openings on the ultimate load carrying capacities of optimally designed perforated steel beams. Test results have shown that compared to lateral stiffeners, ring and vertical stiffeners significantly increase the loadcarrying capacity of perforated steel beams.

• 한국구조물진단유지관리공학회 논문집
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• 제3권3호
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• pp.213-222
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• 1999

On condition that opening located at high shear strength position in H-shaped steel beams with web opening, beams are structurally to be frailed so necessity and efficiency of vertical reinforcement to add horizontal reinforcement already published ahead study. Up to the present study of web opening beams, limited one opening which located in comparatively small shear strength position. But frequently opening area is enlargement by necessity, so width of opening is larger by limit of depth or increasing number of opening. This study carry out experiment to make efficient reinforcing method about strength and deformation of steel beams with web openings. Parameters of this study are openings location, ratio of opening width within opening height and various reinforcing types.

• Structural Engineering and Mechanics
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• 제90권6호
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• pp.611-633
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• 2024

This study intends to investigate the response of multi-cell (MC) beams to flexural loads in which the primary reinforcement is composed of both metallic and non-metallic materials. "Multi-cell" describes beam sections with multiple longitudinal voids separated by thin webs. Seven reinforced concrete MC beams measuring 300×200×1800 mm were tested under flexural loadings until failure. Two series of beams are formed, depending on the type of main reinforcement that is being used. A control RC beam with no openings and six MC beams are found in these two series. Series one and two are reinforced with metallic and non-metallic main reinforcement, respectively, in order to maintain a constant reinforcement ratio. The first crack, ultimate load, deflection, ductility index, energy absorption, strain characteristics, crack pattern, and failure mode were among the structural parameters of the beams under investigation that were documented. The primary variables that vary are the kind of reinforcing materials that are utilized, as well as the kind and quantity of mesh layers. The outcomes of this study that looked at the experimental and numerical performance of ferrocement reinforced concrete MC beams are presented in this article. Nonlinear finite element analysis (NLFEA) was performed with ANSYS-16.0 software to demonstrate the behavior of composite MC beams with holes. A parametric study is also carried out to investigate the factors, such as opening size, that can most strongly affect the mechanical behavior of the suggested model. The experimental and numerical results obtained demonstrate that the FE simulations generated an acceptable degree of experimental value estimation. It's also important to demonstrate that, when compared to the control beam, the MC beam reinforced with geogrid mesh (MCGB) decreases its strength capacity by a maximum of 73.33%. In contrast, the minimum strength reduction value of 16.71% is observed in the MC beams reinforced with carbon reinforcing bars (MCCR). The findings of the experiments on MC beams with openings demonstrate that the presence of openings has a significant impact on the behavior of the beams, as there is a decrease in both the ultimate load and maximum deflection.

• 한국강구조학회 논문집
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• 제15권3호
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• pp.271-279
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• 2003

유공부재의 탄성 및 비탄성 거동을 나타내기 위하여 많은 연구가 이루어져왔으나 단축하중상태의 연구에 집중되어있는 실정이다. 또한, 국부좌굴을 고려한 유공보 설계에 대한 식들은 일반적으로 Darwin의 연구결과를 토대로 하여 사용되고 있으나, 그 연구결과가 단조하중에 집중되어있어 반복하중과 국부좌굴을 고려한 연구의 필요성이 제기되었다. 따라서, 본 연구에서는 반복하중상태에서의 7개의 원형유공보에 대한 실험이 행해졌다. 실험체의 형상 및 변수는 Darwin에 의해 제안된 설계과정에 기초를 두었다. 본 실험을 통하여, 기존 설계식의 타당성, 소성힌지의 영향, 유공 부분의 반복국부좌굴의 영향 등이 관찰 연구되었다.