Nonlinearity of Single Coupled Reinforced Concrete Shear Walls Supported on Two Columns (original) (raw)
Related papers
2021
Modern construction of high-rise and tall buildings depends on coupled shear walls system to resist the lateral loads induced by wind and earthquake hazards. The lateral behavior of this system depends on the structural behavior of its components including coupling beams and shear walls. Although many research studies in the literature investigated coupling beams and shear walls, these studies stopped short of investigating the coupled shear walls as a system. Therefore, in this research, the effect of the coupling beam parameters on the nonlinear behavior of the coupled shear walls system was investigated. The full behavior of a 10-story coupled shear wall system was modeled using a series of finite element analyses. The analysis comprised of testing several coupling beam parameters to capture the effect of each parameter on system response including load-deflection behavior, coupling ratio, crack pattern, and failure mechanism. The results indicated that a span-to-depth ratio equal to two is a turning point for the coupling beam behavior. Specifically, the behavior is dominated by ordinary flexure for a ratio of more than two and deep beam behavior for a ratio of less than two. This study showed that the coupling beam width does not have a significant effect on the coupled shear wall response. Additionally, it was concluded that the excessive coupling beam diagonal reinforcement could significantly affect the coupled shear walls behavior and therefore an upper limit for the diagonal reinforcement was provided. Moreover, limitations on the longitudinal and diagonal reinforcement and stirrups are presented herein. The analysis results presented in this paper can provide guidance for practitioners in terms of making decisions about the coupling ratio of the coupled shear walls.
Nonlinear Finite Element Analysis of Reinforced Concrete Coupled Shear Walls
1991
This thesis is concerned with the development of an inelastic material model to be used in conjunction with the finite element technique to simulate the behaviour of reinforced concrete shear-walls under lateral loads. The proposed computational model is capable of tracing the entire nonlinear response up to ultimate load conditions. The main features of the nonlinear behaviour of concrete and steel are incorporated in the numerical model. These include cracking, nonlinear biaxial stress-strain relationships in concrete up to crushing and yielding of steel. The investigation first considers the linear elastic behaviour of coupled shear-walls then a consistent material model that matches the existing experimental evidence for the behaviour of plain concrete under monotonic biaxial loading is considered. The reinforcing steel is idealized as bilinear uniaxially stressed material. The individual material models are combined with the finite element technique to demonstrate their applica...
Analysis of Reinforced Concrete Coupled Shear Wall Using Finite Element Method
2014
The growth of population density and shortage of land in urban areas are two major problems for all developing countries including India. In order to mitigate these two problems, the designers resort to high-rise buildings, which are rapidly increasing in number, with various architectural configurations and ingenious use of structural materials. An earthquake in India on January 26th, 2001 caused considerable damage to a large number of RCC high-rise buildings. This particular incident has shown that designers and structural engineers should ensure to offer adequate earthquake resistant provisions with regard to planning, design, and detailing in high rise buildings to withstand the effect of an earthquake to minimize disaster. As an earthquake resistant system, the use of shear walls is one of the potential options. The main idea of taking this topic of “ANALYSIS OF REINFORCED CONCRETE COUPLED SHEAR WALL USING FINITE ELEMENT METHOD” is the challenging task in designing of Coupled ...
Analysis of reinforced concrete coupled structural walls via the Beam-Truss Model
Engineering Structures, 2020
The use of an enhanced version of the Beam-Truss Model proposed in a previous study to compute the nonlinear response of reinforced concrete coupled walls is discussed in this paper. The results of the cyclic tests of two seven-story one-quarter scale coupled walls tested in New Zealand are used for model validation. Except for the coupling beams, the specimens were identical. One of the specimens (Wall A) had a conventional arrangement of reinforcement in the coupling beams, whereas the other (Wall B) had beams with diagonal bars. Specimen Wall A showed lateral force-displacement response degradation after reaching a 1.6% roof drift ratio. The degradation in specimen Wall A was due to sliding shear of the beams. Specimen Wall B exhibited stable hysteretic response throughout the test. The authors use two kinds of Beam-Truss Models and compare computed and measured key responses in these tests. Computed responses, measured and not measured in the tests, are also compared with the results of Nonlinear Truss Models reported in the literature. This paper shows that the relatively simple and computational-efficient Beam-Truss Models predicted well important aspects of the response, such as the lateral force-displacement envelope, the sliding shear of the coupling beams in specimen Wall A and the ductile behavior of specimen Wall B.
Analytical model for seismic simulation of reinforced concrete coupled shear walls
Engineering Structures, 2018
Reinforced concrete coupled walls are widely used as the main seismic resistant structural system in high-rise buildings. This paper proposes a new mixed beam-shell model for the seismic analysis of reinforced concrete coupled walls with sufficient efficiency and accuracy on the platform of general finite element software MSC.Marc. Boundary elements at the ends of wall piers are simulated by conventional fiber beam-column elements, while the web of the wall pier is modeled by the layered shell element. Coupling beams are simulated by non-conventional fiber beam-column elements, which can not only take into account the shear and shear-sliding deformation together with various failure modes of conventionally reinforced beams, but also the shear and rebar slip deformation of diagonally reinforced beams. RBE2 link elements are utilized to connect the coupling beams to the wall piers. Eight test specimens reported in the literature are used to validate the proposed model. The mechanism of the coupled wall is thoroughly investigated in terms of the beam deformation, base shear and moment distribution as well as axial force of the wall piers. Furthermore, parametric analyses on specimens with different degrees of coupling and types of reinforcement layouts of coupling beams are conducted. Based on the analyses, the influences of the complex behavior and various modeling parameters of coupling beams on the behavior of coupled wall are revealed quantitatively. As a conclusion of the parametric analyses results, it is recommended that the complicated behavior of coupling beams be accurately considered for most cases in the seismic analysis of coupled wall systems.
Civil engineering infrastructures journal, 2016
Response modification factor (R factor) is one of the seismic design parameters to be considered in evaluating the performance of buildings during strong motions. This paper has tried to evaluate the response modification factor of concrete coupled shear wall structures with various length/depth ratios of spandrel beams. The effect of diagonal reinforcement of spandrel beam was also evaluated on the R factor. The R factor directly depends on overstrength factor and ductility reduction factor. For this purpose, three conventional structures with 5, 10 and 15 story buildings (having various spandrel beam's length/depth ratio with and without diagonal reinforcement) were selected and the nonlinear static analyses were conducted to evaluate their overstrength and ductility reduction factors. Also for a 5-story structure, nonlinear dynamic analysis (time history) was carried out in order to compare the results with nonlinear static analysis. It was concluded that the R factors using ...
Investigation of the Dynamic Behavior of Coupled Shear Wall Systems
The Journal of Engineering, Science and Computing (JESC), 2019
Coupled shear walls are vertical shear walls or elevator cores with openings connected together by beams or slabs. In the present work, the behavior of the reinforced concrete coupled elevator cores of multistory building has been investigated under the seismic loads. The system consists of two U-shaped in the plan monolithic walls, connected at slab levels by beams. Seismic loads were determined according to the International Building Code, IBC-2015. The elastic analysis of the models, was carried out using finite element method (FEM) and the results were compared with the results obtained using the closed form solution (analytical method). Results show that the rigidity of coupling beams has significant effect on the dynamic behavior of the coupled wall system. The presence of connecting beams and the increase of their rigidity resulted in valuable decrease in the period of vibration and deformations of the coupled wall system in all models. Shear stresses in the cross sections of the connecting beams were calculated in accordance to the American ACI Code and Eurocode. It was observed that in some beams it is possible to use only the minimum required reinforcements, whereas in the majority of the cases, designed shear reinforcement must be provided for the connecting beams.
The Dynamic Behavior of Reinforced Concrete Shear Walls
2020
The reinforced concrete buildings are subjected to lateral loads due to wind and earthquake and these forces are predominant especially in tall and slender buildings. In general, the structural response of shear wall strongly depends on the type of loading, aspect ratio of shear wall, size and location of the openings in the shear wall and ductile detailing (strengthening) around the openings of shear walls. The behavior of shear wall remains linearly elastic till certain level of loading; it may not be possible for a shear wall to behave in a same fashion throughout the loading history. Hence, in order to properly proportion and design the shear wall, it is of paramount importance to understand the behavior of shear wall, in linear as well as in non-linear regimes. Shear walls have been conferred as a major lateral load resisting element in a building in any seismic prone zone. It is essential to determine behavior of shear wall in the pre-elastic and post-elastic stage. Shear wall...
Investigating the behavior factor of coupled concrete shear walls with steel coupling beam
Scientia Iranica, 2018
The behavior factor is used to reduce the elastic spectrum ordinate or the forces obtained from a linear analysis in order to take into account the non-linear structural properties. The more accurate this parameter is estimated, the more exact responses of the structures will be obtained. Recently, coupled walls with steel coupling beams are extensively utilized as an efficient system against lateral forces in high-rise buildings. But, there is not enough information about the behavior of these walls during earthquake, and design codes have not suggested any behavior factor for this structural system. Consequently, this paper is devoted to find the behavior factor of this structural system. To achieve this goal, six-, twelve- and twenty-story buildings are assessed. Except for the number of stories, all characteristicsof these buildings are completely similar. Buidlings’ height, the length of the coupling beams and the coupling ratio are key parameters which influence the behavior f...
Procedia Engineering, 2011
Regarding the role of link beams in the seismic behavior of coupled shear walls, in this study, at first a pre-designed concrete link beam of a coupled shear walls system, tested previously under cyclic loading, has been analyzed by Finite Element Modeling (FEM). Then it has been substituted by a steel link beam, and the analyses have been repeated to find out the differences between the hysteretic behavior of the concrete link beam with that of the steel link beam, designed with the same loading. In the verified FEM 8-node elastoplastic solid elements have been used. For the concrete link beams the material has been of 'concrete damage plasticity' type, and for the steel link beams the multi-linear elastoplastic material model has been used. The steel reinforcement bars in concrete elements have been modeled as 'truss' element. The steel link beams have been considered once without stiffeners and once with them to see how they improve its behavior. The embedded length of the steel link beams in the concrete walls has been considered long enough to be able to assume that no sliding occurs between the steel beam and its surrounding concrete. Numerical results show that in case of steel link beams the hysteretic loops does not show any pinching effect, and therefore these link beams are better in seismic energy absorption. The amount of energy absorption can be more than 3 times in comparison with the concrete link beams. Using stiffeners in the steel link beams does not have much effect on their hysteretic behavior, and add their energy absorption capacity only around 10 percent.