scholarly journals Seismic Performance of Hybrid Corrosion-Free Self-Centering Concrete Shear Walls

2022 ◽  
Vol 14 (2) ◽  
pp. 712
Author(s):  
Emad Abraik ◽  
Maged A. Youssef ◽  
Salah F. El-Fitiany
Keyword(s):  
Seismic Performance ◽  
Construction Projects ◽  
Shear Walls ◽  
Seismic Energy ◽  
Design Parameters ◽  
Major Barrier ◽  
Frp Bar ◽  
Free Material ◽  
Hybrid Walls ◽  
Frp Bars

Reinforced concrete (RC) walls are extensively used in high-rise buildings to resist lateral loads, while ensuring an adequate level of ductility. Durability problems, including corrosion of conventional steel reinforcements, necessitate exploring alternative types of reinforcement. The use of glass fiber reinforced polymer (FRP) bars is a potential solution. However, these bars cannot be used in seismic applications because of their brittleness and inability to dissipate seismic energy. Superelastic shape memory alloy (SMA) is a corrosion-free material with high ductility and unique self-centering ability. Its high cost is a major barrier to use in construction projects. The clear advantage of utilizing both SMA and FRP to achieve durable self-centering structures has motivated the development of a composite SMA-FRP bar. This paper investigates the hybrid use of FRP bars and either SMA bars or composite SMA-FRP in concrete shear walls. An extensive parametric study was conducted to study the effect of different design parameters on the lateral performance of hybrid RC walls. The seismic behavior of the hybrid walls was then examined. The hybrid walls not only solved the durability problem but also significantly improved the seismic performance.

Estimation of Seismic Energy Dissipation for Steel Slit Shear Walls Considering Out-of-Plane Buckling

2021 ◽  
Author(s):  
Yiming Ma ◽  
Liusheng He ◽  
Ming Li
Keyword(s):  
Energy Dissipation ◽  
Shear Walls ◽  
Seismic Energy ◽  
Thickness Ratio ◽  
Design Parameters ◽  
Test Results ◽  
Loading Test ◽  
Aspect Ratios ◽  
Out Of Plane ◽  
Energy Dissipation Capacity

Steel slit shear walls (SSSWs), made by cutting slits in steel plates, are increasingly adopted in seismic design of buildings for energy dissipation. This paper estimates the seismic energy dissipation capacity of SSSWs considering out-of-plane buckling. In the experimental study, three SSSW specimens were designed with different width-thickness ratios and aspect ratios and tested under quasi-static cyclic loading. Test results showed that the width-thickness ratio of the links dominated the occurrence of out-of-plane buckling, which produced pinching in the hysteresis and thus reduced the energy dissipation capacity. Out-of-plane buckling occurred earlier for the links with a larger width-thickness ratio, and vice versa. Refined finite element model was built for the SSSW specimens, and validated by the test results. The concept of average pinching parameter was proposed to quantify the degree of pinching in the hysteresis. Through the parametric analysis, an equation was derived to estimate the average pinching parameter of the SSSWs with different design parameters. A new method for estimating the energy dissipation of the SSSWs considering out-of-plane buckling was proposed, by which the predicted energy dissipation agreed well with the test results.

Seismic Behavior of Damage-Reduction Based, Energy Dissipation Composite Shear Walls

2013 ◽  
Vol 742 ◽  
pp. 34-39
Author(s):  
Hong Ying Dong ◽  
Wan Lin Cao ◽  
Hai Peng Wu ◽  
Fang Fang Xu
Keyword(s):  
Energy Dissipation ◽  
Shear Walls ◽  
Seismic Energy ◽  
Shear Wall ◽  
Core Structure ◽  
Design Parameters ◽  
The Core ◽  
Damage Reduction ◽  
Cfst Columns ◽  
Composite Shear

A new damage-reduction based composite shear wall was proposed. It combines with three different energy dissipation units, which are the CFST column, SP deep beam and RC strip. The CFST column is set to be exposed outside or concealed inside the concrete. CFST columns and SP deep beams constitutes the core structure. During loading, RC strips between columns work with the core structure so as to reduce the damage and consume the energy. Four specimens with different design parameters, including 2 shear walls with exposed CFST columns and 2 with concealed CFST columns, were tested under horizontal cyclic loading. The load-bearing capacity, stiffness, hysteretic property, ductility, and failure characteristic of specimens have been analyzed. Results show that the deformation of this wall is just between that of the slotted shear wall and the entire shear wall. The RC strips reduce the damage and the core structure presents ductile behavior during load. The new wall is designed based on damage-reduction and it shows good seismic energy dissipation mechanics. It can be applied to the design of shear wall in high-rise buildings.

Influence of different design parameters on the seismic performance of partially grouted masonry shear walls

2021 ◽  
Vol 239 ◽  
pp. 112058
Author(s):  
Sebastián Calderón ◽  
Cristián Sandoval ◽  
Gerardo Araya-Letelier ◽  
Ernesto Inzunza ◽  
Oriol Arnau
Keyword(s):  
Seismic Performance ◽  
Shear Walls ◽  
Design Parameters

scholarly journals Seismic performance of steel moment and hinged frames with rocking shear walls

2021 ◽  
Author(s):  
Mehrdad Piri ◽  
Ali Massumi
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Shear Walls ◽  
Seismic Energy ◽  
Shear Wall ◽  
3D Models ◽  
Initial Position ◽  
Economic Effects ◽  
Moment Frames ◽  
Nonlinear Time History

Abstract The addition of a rocking structural system will soften the connection between a foundation and superstructure and help the beam-column connections to become softer than typical ones. These structures, with the addition of rocking structural systems, follow the elastic gap opening mechanism to soften the structural seismic response. Post-tensioned energy dissipating devices and dampers are used in rocking systems to enable the structure to return to its initial position (self-centering) and to dissipate seismic energy, respectively. The current study investigated the use of a rocking shear wall system in steel moment-resistant and hinged frames and determined the amount of damage and the economic effects on the structures. For this purpose, 3D models of 3-, 9-, and 20-story SAC-project steel frames were modeled and validated according to FEMA-355C and then a hybrid rocking shear wall was added to them. The structures were designed and modeled according to common seismic codes and were analyzed using nonlinear time history when subjected to a series of records from FEMA-355C. The results showed that the use of a hinged frame attached to a rocking concrete shear wall (HFR) increased the fundamental period and inter-story displacement and decreased the amount of steel used in the 3-, 9-, and 20-story models compared to similar models with fixed connections in moment frames (MFR). The HFR shear wall models exhibited better seismic performance than MFR models, which increased their load-bearing capacity and reduced their weight, which reduced construction costs.

scholarly journals Experimental Investigation into the Seismic Performance of Prefabricated Reinforced Masonry Shear Walls with Vertical Joint Connections

2021 ◽  
Vol 11 (10) ◽  
pp. 4421
Author(s):  
Zhiming Zhang ◽  
Fenglai Wang
Keyword(s):  
Seismic Performance ◽  
Cross Sections ◽  
Shear Walls ◽  
Construction Method ◽  
Shear Capacity ◽  
Initial Stiffness ◽  
Equivalent Viscous Damping ◽  
Displacement Ductility ◽  
Reinforced Masonry ◽  
Cracking Performance

In this study, four single-story reinforced masonry shear walls (RMSWs) (two prefabricated and two cast-in-place) under reversed cyclic loading were tested to evaluate their seismic performance. The aim of the study was to evaluate the shear behavior of RMSWs with flanges at the wall ends as well as the effect of construction method. The test results showed that all specimens had a similar failure mode with diagonal cracking. However, the crack distribution was strongly influenced by the construction method. The lateral capacity of the prefabricated walls was 12% and 27% higher than that of the corresponding cast-in-place walls with respect to the rectangular and T-shaped cross sections. The prefabricated walls showed better post-cracking performance than did the cast-in-place wall. The secant stiffness of all the walls decreased rapidly to approximately 63% of the initial stiffness when the first major diagonal crack was observed. The idealized equivalent elastic-plastic system showed that the prefabricated walls had a greater displacement ductility of 3.2–4.8 than that of the cast-in-place walls with a displacement ductility value of 2.3–2.7. This proved that the vertical joints in prefabricated RMSWs enhanced the seismic performance of walls in shear capacity and ductility. In addition, the equivalent viscous damping of the specimens ranged from 0.13 to 0.26 for prefabricated and cast-in-place walls, respectively.

Thermal effect on fiber reinforced polymer reinforced concrete slabs

2008 ◽  
Vol 35 (3) ◽  
pp. 312-320 ◽  
Author(s):  
A. Zaidi ◽  
R. Masmoudi
Keyword(s):  
Thermal Effect ◽  
Concrete Cover ◽  
Fiber Reinforced Polymer ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
Reinforced Polymer ◽  
Frp Bar ◽  
Frp Bars ◽  
Concrete Interface

The difference between the transverse coefficients of thermal expansion of fiber reinforced polymer (FRP) bars and concrete generates radial pressure at the FRP bar – concrete interface, which induces tensile stresses within the concrete under temperature increase and, eventually, failure of the concrete cover if the confining action of concrete is insufficient. This paper presents the results of an experimental study to investigate the thermal effect on the behaviour of FRP bars and concrete cover, using concrete slab specimens reinforced with glass FRP bars and subjected to thermal loading from –30 to +80 °C. The experimental results show that failure of concrete cover was produced at temperatures varying between +50 and +60 °C for slabs having a ratio of concrete cover thickness to FRP bar diameter (c/db) less than or equal to 1.4. A ratio of c/db greater than or equal to 1.6 seems to be sufficient to avoid splitting failure of concrete cover for concrete slabs subjected to high temperatures up to +80 °C. Also, the first cracks appear in concrete at the FRP bar – concrete interface at temperatures around +40 °C. Comparison between experimental and analytical results in terms of thermal loads and thermal strains is presented.

Effects of Brace Stiffness and Nonlinearity of Viscous Dampers on Seismic Performance of Structures

2021 ◽  
pp. 2150188
Author(s):  
Siyuan Li ◽  
Yung-Tsang Chen ◽  
Y. H. Chai ◽  
Bo Li
Keyword(s):  
Seismic Performance ◽  
Structural Performance ◽  
Design Parameters ◽  
Viscous Dampers ◽  
Story Structure ◽  
Design Efficiency ◽  
Time Stepping ◽  
Seismic Hazard Mitigation ◽  
Method Effects ◽  
Supplemental Dampers

In the applications of supplemental dampers for seismic hazard mitigation, the supporting braces for the dampers are considered an important component for ensuring an efficient energy dissipation in the structure. Despite their importance, studies on the effects of the brace stiffness and the velocity exponent in the case of nonlinear viscous dampers are rather limited. In this paper, a numerical time-stepping method is developed for computing the seismic response of the structure with supporting braces and nonlinear viscous dampers. Using the proposed method, effects of the parameters of the nonlinear damper-brace systems are investigated, using first a single-story structure, followed by multi-story buildings. Results indicated that the design parameters for the dampers and supporting braces may be combined in numerous ways to satisfy a given set of structural performance objectives, but the brace stiffness can be minimized to achieve design efficiency in the range of velocity exponent commonly used for seismic applications of nonlinear viscous dampers. Results also indicated that for a set brace stiffness, if the dampers are optimally designed, the velocity exponent has an insignificant effect on the structural seismic performance objectives considered in this paper.

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