Figure - available from: ISRN Civil Engineering
This content is subject to copyright. Terms and conditions apply.
Source publication
Earthquake causes considerable damage to a large number of RCC high-rise buildings and tremendous loss of life. Therefore, 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 and minimize disa...
Citations
... A simplified wide-column model was innovated by other structural shear walls using the wall's energy dissipation and inelastic behavior [21]. Bhunia et al. [22] presented a conceptual design for shear walls and improved solutions to compare performance-based strategies. Wei et al. [23] studied mesh boundary motion by simulating wind effects and presented a method to focus on clustered boundary meshes for turbulent flow simulation. ...
... Where two parameters of H a and / zH are dimensionless [43]. Warping tensions are mentioned as follows: (22) Equation (22) indicates that the ESWO performs properly when some parameters are improved, considering stress reduction by the device. ...
... Where two parameters of H a and / zH are dimensionless [43]. Warping tensions are mentioned as follows: (22) Equation (22) indicates that the ESWO performs properly when some parameters are improved, considering stress reduction by the device. ...
Today, many strategies have been proposed to improve the behavior of tall buildings under seismic load. Drifts, torsion, and structure period are essential parameters affecting high-rise building behavior. In addition, the stress concentration at the end wing of shear walls is another critical subject in high-rise buildings, which was resolved using end shear walls. The end shear wall connects the end of two shear walls in high-rise buildings without opening. In this study, a new end shear wall connects the end of shear walls in a high-rise building with regular openings (ESWO). Therefore, two 30-story RC buildings with and without end shear walls with opening were modeled by a nonlinear time history analysis under seismic load. The drift was decreased by 49% in a 30-story building with a new end shear wall. Moreover, the residual displacement of 30-story buildings with end shear walls with opening was decreased by 67%.. The time history nonlinear analysis investigation indicated that the end shear walls with opening declined the maximum displacement by 62% in tall buildings by Open Sees software. The reduction of the standard deviation of data increased the confinement in 30-story drifts in the X and Y directions by end shear walls with opening. Based on the results, the performance of the end shear walls with the opening was appropriate in the seismic behavior of high-rise buildings.
... simplified model for the analysis of free plan buildings investigated by researchers and shear wall core modeled by wide column element and finally a model devised by shear wall, energy dissipation system and inelastic behavior of walls [11]. Also, a conceptual design investigated in coupled shear walls and indicated by comparison performance-based seismic design and conventional design based on linear response spectrum, they realized that PBSD significantly improved [12]. Another study about seismic behavior of steel frames with RC shear walls searched by researchers. ...
Many factors affect tall buildings under the influence of earthquake forces. According to the conducted studies, more tensions have been observed in the end wings of shear walls. The end shear wall is used to reduce tensions and to improve the performance of shear walls in tall buildings. In this study, 10-story, 30-story and 50-story concrete buildings with square plans were modeled and two cases of the moment-resisting frame with shear wall and moment-resisting frame with end shear wall, which were under the influence of earthquake and linear static analysis have been investigated. In this analysis, the buildings were torsioned and the results of the analysis showed that the values of the drifts, roof displacement and first period in the structure with the end wall are about 50 % percent less than of that of the building without the end wall, also, On the other hand, with the presence of the end wall in structure the ratio (∆max/∆avg) is more than 1.2, so, the use of the end wall led to a more appropriate behavior of warping in comparison to concrete square frames with no end walls.
... In this regard, Meftah and Mohri (2013), McGinnis et al. (2013), Hadidi et al. (2003), Abdollahzadeh and Malekzadeh (2013), Eljadei (2012), Bhunia et al. (2013) and Khatami et al. (2012) assessed the behavior of shear coupled walls under static and dynamic loads. ...
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 nonlinear time history analysis and nonlinear static analysis are almost the same. The results also indicate that by increasing the height of the structure, the overstrength reduction factor decreases; while the ductility reduction factor increases. Also, the response modification factor decreases with increasing length/depth ratio of spandrel beams. The coupled shear walls with diagonal reinforcement in spandrel beams have a greater R factor.
The use of coupled shear walls has been one of the potential options as an earthquake resistant system in reinforced concrete composite high-rise buildings in recent times. Coupled shear walls consist of two shear walls connected intermittently by beams over their height. The behavior of coupled shear walls is strongly influenced by the coupling beams. When the coupled shear walls are subjected to earthquake motion, energy dissipates in the coupling beams and, depending on the design, also at the base of the shear walls. However, it is seen from past research that there is an inconsistency regarding behavior of such coupling beams, especially regarding their modeling parameters (the size of the coupling beam), evaluative parameters (plastic rotation and yield moment capacities) and their unrealistic boundary conditions. This paper aims to achieve consistency regarding the behavior of coupling beams and feasible boundary conditions using both experimental and numerical analyses.
Tall building development is rapidly growing almost everywhere in the world acquainting new difficulties that need to be met with, through engineering evaluation. In tall buildings, lateral loads generated by earthquake or wind load are frequently resisted by providing coupled shear walls. But as the height increases, the building becomes taller and the efficiency of the tall building greatly depends on lateral stiffness and resistance capacity. So, a system called outrigger is introduced which improves overturning stiffness and strength by connecting shear wall core to outer columns. When the Structure is subjected to Lateral forces, the Outrigger and the columns resist the rotation of the core and thus significantly reduce the lateral deflection and base moment, which would have arisen in a free core. During the last three decades, numerous studies have been carried out on the analysis and behaviour of outrigger structures. But this question is remained that how many outriggers system is needed in tall buildings. (Using Staad-Pro)
The performance of coupling beams under cyclic loadings is evaluated when they
have openings with different configuration. The study is performed through
experimental examination on four reduced scale coupling beams. The testing is done
in the Concrete Laboratory at the Housing and Building National Research Center,
Cairo, Egypt. Square openings are constructed on three specimens with different
configurations whereas the fourth specimen kept without openings for the
comparison matter. Two openings are fabricated at top and bottom of the diagonal
bars in one beam specimen. Another specimen contains two openings at left and right
of the diagonal bars. The last specimen has four square openings placed at top-bottom
and left-right of the diagonal bars of the coupling beam. The yield and ultimate tensile
strength of the reinforcement steel bars are 510 and 720 MPa, respectively with
elastic modulus of 200 GPa. The concrete characteristic strength is 38 MPa. All
specimens were tested under laterally cyclic loading to simulate the subjected loads
on coupled shear walls. A special complicated setup is utilized for that issue. The
results are recorded during testing and at the end of each cycle. The forcedeformation
relationships are recorded and their corresponding hysteresis loops are
plotted. The cracks patterns are also marked and recorded. From the obtained results,
one may observe that, in case of using two openings located at right and left (near the
shear walls), the stiffness of the coupling beam is slightly decreased. The coupling
beams stiffness is decreased by ~8.5% for the other pattern of two openings and by
~13.5% in case of using four openings.
This paper presents a system for tracking the maximum power point (MPP) and output voltage regulation of photovoltaic cells. The system includes two stages of cascading dc/dc converters: the first one is a boost converter used for tracking the MPP using the perturb and observe algorithm. Meanwhile, a buck converter regulates the output voltage employing the active disturbance rejection control based on an extended state observer and the differential flatness property. The hardware architecture was modeled using high‐level tools of hardware abstraction and implemented in a FPGA Artix‐7 made by Xilinx. Finally, the performance of the proposed system is shown through a series of experiments that consisted of changing the irradiance and temperature conditions and changes in the system parameters.
