On the effect of reduced boundary elements in steel shear walls

2017 ◽  
Vol 8 (1) ◽  
pp. 2-24
Author(s):  
Sayed Behzad Talaeitaba ◽  
Hamed Esmaeili ◽  
Mohammad Ebrahim Torki
Keyword(s):  
Load Capacity ◽  
Shear Walls ◽  
Steel Structures ◽  
Boundary Elements ◽  
Reduced Form ◽  
Base Shear ◽  
Ultimate Load Capacity ◽  
Content Type ◽  
Local Boundary ◽  
Stiffness Reduction

Purpose Steel shear walls have recently received exclusive remark. Respective of most building code requirements, design of shear wall vertical boundary elements (VBEs) and local boundary elements (LBEs) against web yielding triggers exaggerated stiffness. The extent of stiffness reduction effects in boundary elements thus calls for more exhaustive investigation. The paper aims to discuss these issues. Design/methodology/approach To this end, FEM-based push-over curves demonstrating base shear vs roof displacement, and von Mises plastic strains were scrutinized in half-scale and full-size models. Analyses were in perfect conformity with experimental data. Findings With reference to the AISC requirement, up to 35 percent decrease in the VBE moments of inertia could be imparted in higher levels without the ultimate load capacity nor displacement to failure being reduced. Also considered was open shear walls with reduced or minimum-design LBEs, the latter being used in continuous or abridged form. LBEs could be used with a moment of inertia 80 percent smaller than required if only used in a continuous form. The effect due to opening geometry was negligible on loading capacity but distinguished on the post-yielding buckling-induced softening. Practical implications Light-weight design of low- to medium-level steel structures against earthquake loads. Originality/value With respect to continuous walls, the results are more comprehensive than those existing in the literature in that they combine the effects due to scale and orientation (horizontal or vertical) of boundary elements. The results for open shear walls are not only comprehensive but also original in a sense that they account for the influences induced by the opening type (door or window), orientation (horizontal or vertical), and design (full-length or abridged) of boundary elements, in reduced form, on the lateral stiffness of the frame.

Ultimate load capacity of square shear plates with circular perforations

1988 ◽  
Vol 15 (3) ◽  
pp. 470-476
Author(s):  
A. Martin ◽  
S. F. Stiemer ◽  
P. Osterrieder
Keyword(s):  
Load Capacity ◽  
Shear Walls ◽  
Steel Structures ◽  
Hole Size ◽  
Ultimate Capacity ◽  
Ultimate Load Capacity ◽  
Element Mesh ◽  
Black And White ◽  
Inelastic Material ◽  
Shear Buckling

Working platforms and support caissons of offshore steel structures are often designed with plate boxes or plate girders. The important shear walls or shear webs must often be perforated to allow utilities, etc., to pass through. The failure mode of these large perforated shear panels is typically shear buckling, usually in the plastic range. The paperpresents results of a finite element buckling analysis with inelastic material behaviour and gives general guidelines for the ultimate capacity design of perforated shear plates. The parameters affecting the ultimate capacity of square plates with circular perforations under uniform shear stress were investigated using the incremental structural analysis program NISA83. Nonlinearities in material properties and geometry were taken into account in the calculation of ultimate capacities of each perforated shear plate.The parameters investigated in the study were hole size for a concentric hole and hole location for a constant hole size. Only single unreinforced round holes were considered. Three capacities were calculated for each variation of these parameters: the ultimate in-plane capacity, the elastic buckling capacity, and the ultimate elastic-plastic buckling capacity.In order to check the input data and to provide concise display of the results, a graphic postprocessor was developed as part of the research. The program NISPLOT uses colour graphics to generate plots of the nodes, element mesh, the deflected shape, and stress patterns of the loaded plates. The plots were reduced to black and white for this paper. Key words: girders, holes, steel, ultimate capacity, buckling.

scholarly journals Numerical Analysis of Single-Angle Steel Member Under Tension Force with Different End Deformations

2020 ◽  
Vol 6 (8) ◽  
pp. 1520-1533
Author(s):  
Ahmed M. Sayed
Keyword(s):  
Stress Distribution ◽  
Cross Section ◽  
Ultimate Load ◽  
Load Capacity ◽  
Steel Structures ◽  
Ultimate Load Capacity ◽  
Axis Direction ◽  
Steel Members ◽  
The Mean ◽  
Experimental Findings

Steel members with a single-angle cross-section are widely used, but some of their behaviours under loads are not considered by design codes, necessitating related research. This study is carried out on fifty steel single-angle members focused on the stress distribution behaviour and the ultimate axial load capacities under different end deformations through 3-dimensional Finite Element (FE) simulations and comparison with previous experimental findings. FE modeling is capable of modeling steel structures with high accuracy. Based on the results, the length of the angle affects neither the shape of the stress distribution nor the ultimate load capacity of the element. The end deformations affect the stress distribution on the member angle cross-section, including the ultimate load capacity. The end deformations which restricted deformations in the two directions perpendicular to the load axis are found to be optimal, with an average increase in load capacity by a factor of 1.96 for an equal angle and 2.21 for an unequal angle compared with the capacities calculated for single angles with deformations allowed in all directions. The appearance of a compression zone on the unconnected angle leg reduces the ultimate load capacity. The current design code (ANSI/AISC-360) can be adopted to calculate the ultimate load in the case of no deformation in the y-axis direction and no deformations in the x- and y-axis directions where the mean ratios of PNum/Pcode are 1.24 and 1.34 respectively. However, the code does not agree with the end deformations of free deformations and no deformation in the x-axis direction for either equal or unequal angles where the mean ratios of PNum/Pcode are 0.64 and 0.79 respectively, which is unsafe.

scholarly journals Hysteretic Assessment of Steel-Concrete Composite Shear Walls

2019 ◽  
Vol 8 (2) ◽  
pp. 5640-5645
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Experimental Test ◽  
Ultimate Load ◽  
Steel Plate ◽  
Load Capacity ◽  
Plate Thickness ◽  
Shear Walls ◽  
Ultimate Load Capacity ◽  
Composite Shear

This paper focuses on the hysteretic assessment of steel-concrete composite shear walls with reinforced concrete on one side of the steel plate. Finite element software ABAQUS is utilised to conduct this research. An experimental test on a composite shear wall is simulated to do the verification of the modelling. Then, modelling result is compared with the experimental test result which shows an insignificant difference between them and therefore uncovers the accuracy of the modelling. Thereafter, different parameters are considered to investigate their effects on the response of the walls. Thickness of reinforced concrete, steel plate thickness, and number of shear studs are studied as parameters. It is concluded that changing reinforced concrete thickness and number of shear studs do not considerably affect the ultimate load capacity, ductility, and energy dissipation of the walls. However, increasing the steel plate thickness enhances the ultimate load capacity, ductility, and energy dissipation. In addition, out-of-plane displacement of the walls is evaluated.

scholarly journals A Numerical Investigation on the Structural Behavior of Deficient Steel Frames Strengthened using CFRP Composite

2018 ◽  
Vol 20 (1) ◽  
pp. 1 ◽  
Author(s):  
Amir Hamzah Keykha
Keyword(s):  
Numerical Study ◽  
Load Capacity ◽  
Steel Frames ◽  
Steel Structures ◽  
Independent Study ◽  
Fiber Reinforced Polymers ◽  
Structural Behavior ◽  
Ultimate Load Capacity ◽  
Hollow Section ◽  
Cfrp Composite

Carbon fiber reinforced polymers (CFRP) is one of the materials that is used to strengthen steel structures. Most studies on CFRP strengthening steel on structures have been done on beams and steel columns. No independent study has studied the effect of CFRP strengthening on the structural behavior of steel frames having initial deficiency.The deficiency in steel structures may be created due to the errors caused by construction and others.This study aims to carry out a numerical study on the efficiency of CFRP sheet on strengthening square hollow section (SHS) steel frames having initial deficiency. Seven specimens, five of which were strengthened using CFRP sheets, were analyzed. ANSYS software was used to analyze the SHS steel frames. The results showed that the coverage length, the width, and the number of CFRP layers have a significant effect on increasing and recovering the ultimate load capacity of the SHS steel frames having initial deficiency.

Simplified probabilistic seismic assessment of dampers in tall and braced structures in buildings

2020 ◽  
Vol 18 (5) ◽  
pp. 1037-1052
Author(s):  
Tanuja Singh ◽  
Megha Kalra ◽  
Anil Kumar Misra
Keyword(s):  
Industrial Structure ◽  
Vibration Reduction ◽  
Steel Structures ◽  
Base Shear ◽  
Content Type ◽  
Fluid Viscous Dampers ◽  
Adjacent Buildings ◽  
Story Drift ◽  
Probabilistic Seismic Assessment ◽  
Resistant Structure

Purpose The paper aims to focus on adjacent buildings response, equipped with damper, to analyze the vibration reduction in the nearby buildings. The nearby buildings were also equipped with dampers. The occurrence of adjacent buildings with adequate or inadequate space in between is a common phenomenon. However, many a times not much attention is paid to provide or check gap adequacy or to connect the two buildings suitably to avoid pounding of two structures on each other. This study emphasizes the utility of providing a damper in between two adjacent buildings for better performance. Design/methodology/approach The two steel structures taken for study are prototype of two structures normally found in industrial structure such as power plant, where in one of boiler structure is often tall and braced and short structure of turbine building which is moment resistant, modeled in SAP. There could be similar such structures which are often connected to a platform or a walkway with a sliding end, so as not to transfer horizontal force to other structures. If the advantage of stiffness of tall braced structure is taken into account, shorter structure can be suitably connected to braced structure to transfer forces during seismic cases under nonlinear conditions, thereby avoiding pounding (incase gap is too less), reducing response and thus optimizing the section sizes. The structures were subjected to El Centro earthquake, to simulate MCE (which could be the other site TH scaled up as desired for real site PGA), and damper location and parameters were varied to find optimum value which offers reduced base shear, reduced top floor displacement and minimum inter story drift and highest energy absorption by fluid viscous dampers. Findings The findings show that taller structures, which are braced, have more stiffness; the effect of damper is more pronounced in reducing displacement of shorter moment resistant structure to the tune of 60%, with suitably defined Cd value which is found to be 600 KNs/m for the present study. Thus, advantage of stiffener structure is taken to leverage and reduce the displacement of shorter moment resistant structure in reducing its displacement under nonlinear conditions of seismic case. Originality/value This work shows the original findings, of the adjacent buildings response, equipped with damper, to analyze the vibration reduction on other buildings which were planned to be constructed nearby.

Experiment Study on Compressive Membrane Action of Slab Strips Restrained by Shear Walls

2009 ◽  
Vol 417-418 ◽  
pp. 805-808
Author(s):  
Qing Xiang Wang ◽  
Gang Wang ◽  
Zhong Jun Li
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
Shear Walls ◽  
Lateral Force ◽  
Membrane Action ◽  
Ultimate Load Capacity ◽  
Previous Hypothesis ◽  
Rc Slab ◽  
Lateral Restraint ◽  
Compressive Membrane Action

Subjecting to the compressive membrane action (CMA), the ultimate load capacity of the reinforced concrete (RC) slab with lateral restraint would be improved obviously. Test of 12 one-way slab specimens restrained by shear-walls was carried out to investigate the properties of the slab strips’ compressive membrane action. The reduced-size specimens were designed to keep the ratios of shear-walls’ restraint stiffness to slab strips’ flexural stiffness unchanged. One horizontal testing instrument was first used to record the development of the slabs’ lateral restraint forces. The ultimate loads of slab strips with certain lateral restraint stiffness gave an average 38.3% rise from the calculations of upper-bound method. Though the increment of slab’s ultimate load was due to the additional moment formed by the lateral restraint force, the results showed that the peak of lateral force lagged of the slab strips’ ultimate load, which was different from the previous hypothesis. Various parameters which affect the development of CMA were also investigated, such as the shear-wall’s thickness, axial load on the walls, the slab strips’ span-height ratio and reinforcement percentage.

Numerical analysis of reinforced concrete beams strengthened in shear using carbon fiber reinforced polymer materials

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sabiha Barour ◽  
Abdesselam Zergua
Keyword(s):  
Finite Element ◽  
Ultimate Load ◽  
Load Capacity ◽  
Nonlinear Finite Element ◽  
Fiber Reinforced Polymer ◽  
Analytical Models ◽  
Ultimate Load Capacity ◽  
Content Type ◽  
Reinforced Polymer ◽  
The Difference

Purpose This paper aims to analyze the performance of reinforced concrete (RC) beams strengthened in shear with carbon fiber-reinforced polymer (CFRP) sheets subjected to four-point bending. Design/methodology/approach ANSYS software is used to build six models. In addition, SOILD65, LINK180, SHELL181 and SOLID185 elements are used, respectively, to model concrete, steel reinforcement, polymer and steel plate support. A comparative study between the nonlinear finite element and analytical models, including the ACI 440.2 R-08 and FIB14 models as well as experimental data, is also carried out. Findings The comparative study of the nonlinear finite element results with analytical models shows that the difference between the predicted load capacity ranges from 4.44%–24.49% in the case of the ACI 440.2 R-08 model, while the difference for FIB14 code ranges from 2.69%–26.03%. It is clear that there is a good agreement between the nonlinear finite element analysis (NLFEA) results and the different expected CFRP codes. Practical implications This model can be used to explore the behavior and predict the RC beams strengthened in shear with different CFRP properties. They could be used as a numerical platform in contrast to expensive and time-consuming experimental tests. Originality/value On the basis of the results, a good match is found between the model results and the experimental data at all stages of loading the tested samples. Load capacities as well as load deflection curves are also presented. It is concluded that the differences between the loads at failure ranged from 0.09%–6.16% and 0.56%–4.98%, comparing with experimental study. In addition, the increase in compressive strength produces an increase in the ultimate load capacity of the beam. The difference in the ultimate load capacity was less than 30% when compared with the American Concrete Institute and FIB14 codes.

Analysis of Multi-Story Buildings with Hybrid Shear Wall - Steel Bracing Structural System

2021 ◽  
Author(s):  
Shubam Sharma ◽  
Aditya Kumar Tiwary
Keyword(s):  
Finite Element ◽  
Shear Walls ◽  
Steel Structures ◽  
Lateral Load ◽  
Structural System ◽  
Base Shear ◽  
Time Period ◽  
Story Drift ◽  
Overturning Moment ◽  
Comparative Results

Abstract Numerous studies were contemplated on the structures with distinctive structural configuration and ample amount of work is currently being performed through the investigation of the response of individual behavior of shear walls and bracings by varying configurations and their material properties. Seismic design philosophies had mentioned firmly that a structure must accomplish Life Safety (LS) and Performance Level (PL) for both reinforced concrete and steel structures. This study is anchored on prevailing lateral load resisting system which is virtuous but not adequate to retain vigorous ground motion or acceleration. To overwhelm this problem, an attempt was made to familiarize a new lateral load resisting system formulated by the amalgamation of two different existing lateral load resisting systems, specifically shear walls and bracings. The hybrid structural system embraces two distinctive lateral load resisting techniques, shear walls, and bracings for moment-resisting frame. A numerical finite element study was carried out by the linear dynamic method on the response of structure subjected to seismic condition and an optimal configuration of the different structural patterns is assured by using numerous possible patterns of a hybrid structural system using finite element-based software. The criteria contemplated for study including time period, base shear, overturning moment, story drift ratio, and story displacement are compared with different models and the optimal structure is concluded based upon the recital. The comparative results revealed that there is a reduction noticed in the fundamental time period, and story displacement, where as there is negligible increment in base shear and overturning moment for the hybrid structural system as compared to other configurated models.

Seismic Consolidation of ’60s Pilotis R.C. Building for Social Housings with SCC-Steel Shear Walls

2014 ◽  
Vol 638-640 ◽  
pp. 1937-1942 ◽  
Author(s):  
Marco Andreini ◽  
Anna de Falco ◽  
Linda Giresini ◽  
Mauro Sassu
Keyword(s):  
Social Housing ◽  
Load Capacity ◽  
Shear Walls ◽  
Base Shear ◽  
Ground Floor ◽  
Steel Columns ◽  
The Poor ◽  
Seismic Forces

The reinforcement of a r.c. building for social housing has been achieved by using Steel-Concrete Composite (SCC) walls at the ground floor, preceded by temporary brick pillars for structural deficiency to vertical loads, due to the poor load capacity of the r.c. columns. The SCC walls have been realized first by placing steel columns on both sides of the existing pillars and, after removal of the temporary brick piers, by merging the steel columns in the cast of the new walls. The top of the walls has been connected to the upper floor in order to ensure the diffusion of the seismic forces. Foundations have been reinforced to support the seismic base shear.

scholarly journals Strength Assessment of Rectangular Plates Subjected to Extreme Cyclic Load Reversals

2020 ◽  
Vol 8 (2) ◽  
pp. 65 ◽  
Author(s):  
Mesut Tekgoz ◽  
Yordan Garbatov
Keyword(s):  
Cyclic Load ◽  
Yield Criterion ◽  
Load Capacity ◽  
Initial Imperfection ◽  
Material Model ◽  
Rectangular Plates ◽  
Ultimate Load Capacity ◽  
Strength Assessment ◽  
Stiffness Reduction ◽  
Structural Capacity

The objective of this study is to investigate the strength of the rectangular plates subjected to cyclic load reversals with varying strain ranges. The finite element solution is implemented to estimate the load-carrying capacity. The influence of the initial imperfections, plate thicknesses and aspect ratio parameters have been accounted for. The cyclic response is predicted by using the material model assumed to follow the combined non-linear isotropic and kinematic strain hardening rules with Von Misses yield criterion accounting for the Bauschinger effect. It has been shown that the type of plastic formation during the cyclic load has a significant influence on the structural capacity and stiffness reduction. The initial imperfection has a significant impact on the ultimate load capacity reduction where the uni-modal initial imperfection type leads to a more stable load transition and plastic formation, reducing the structural capacity during the cyclic load exposure.

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