Behavior Of Shear Walls Research Articles

Effect of Vertical Location of Post-Opening on Seismic Behaviour of RC Shear Wall: Experimental and Numerical Analysis

The seismic performance of reinforced concrete (RC) shear walls with post-openings is critical in civil engineering. This study investigates the influence of post-opening positions on the seismic behaviour of RC shear walls through both experimental and numerical approaches. Four shear wall specimens with varying positions of post-openings were subjected to pseudo-static tests. Additionally, Finite Element Method (FEM) simulations were employed to further analyse the structural responses of shear walls with post-openings. The results show that the vertical position of post-openings significantly affects the failure mode, peak bearing capacity, and overall seismic performance. Peak bearing capacity reductions were observed, with central and bottom openings diminishing capacity by up to 17.5% and 15.1%, respectively, while top openings had a minimal impact. Openings also influenced pre-crack initiation, yielding behaviour, and stiffness degradation, with central openings causing the most significant effects. The ductility and energy dissipation capacities of the shear walls were also affected by opening positions. Bottom post-openings led to a maximum ductility reduction of 18.4%, while top openings increased ductility by up to 24.6%. Energy dissipation capacity decreased with lower post-opening locations, with central and bottom openings reducing capacity by 78.9% and 63.0%, respectively. These findings emphasize the importance of considering opening location in the seismic design of RC shear walls to optimize structural performance.

Investigating the behavior of vertical trapezoidal CSSWs stiffened with flat steel plate

Steel shear wall (SSW) is an efficient system used to construct and improve many structures over the past decades. The main weakness of the traditional flat plate SSW is the premature buckling of the plate, for which the corrugated steel shear wall (CSSW) is a suitable alternative. However, the reduced resistance of CSSW compared to flat SSWs is a disadvantage. In this research, their reinforcement by flat steel plates with different dimensions and thicknesses has been used to improve the behavior of vertical trapezoidal steel shear walls (VTSSW). The samples studied in this research were subjected to cyclic loading after verification in Abaqus finite element software. The outcomes showed that reinforcing CSSWs with flat plates increased strength and energy absorption between 6 to 63% and 16 to 92%, respectively. Also, the equivalent viscous damping has increased between 5 and 82%. Also, due to strengthening the CSSWs, the pinching phenomenon in the hysteresis curves has been reduced, and the sudden decrease in strength after buckling in the CSSWs without stiffener has been significantly reduced.

The effect of the floor-wall interaction on the post-elastic rocking behaviour of segmented CLT shear walls

This paper investigates the impact of floor-wall interaction on the lateral rocking behaviour of two-panel segmented Cross-Laminated Timber (CLT) shear walls through experimental testing and numerical analyses. The study extends a simplified equivalent spring modelling approach to the post-elastic domain to accurately simulate the effects of floor-wall interaction. Experimental withdrawal tests on four types of floor-to-wall connections, utilizing Fully Threaded Screws (FTSs) and Partially Threaded Screws (PTSs) at varying inclinations, revealed that FTSs exhibited higher stiffness and load-carrying capacity but lower deformation capacity compared to PTSs. The maximum force of FTS connections was about twice that of PTS connections, while PTS connections achieved ultimate displacements up to seven times greater. Numerical analyses using a parametric framework showed that floor-wall interaction increases the stiffness and lateral load-carrying capacity of segmented shear walls, with a significant reduction in deformation capacity. These analyses also demonstrated that the equivalent spring can effectively replicate the influence of floor-wall interaction on shear wall lateral response. Expressions for calculating the strength and ductility of this equivalent spring were developed, considering a limited set of geometric and mechanical parameters. These expressions provide a simplified yet accurate method for estimating the effects of floor-wall interaction. The findings suggest that understanding the interaction between floor and wall elements is crucial for optimizing the performance of segmented CLT shear walls in seismic and lateral load scenarios.

Dynamic Analysis of Multi-Storey Building for Minimization of Lateral Displacement due to Earthquake Using Shear Wall

Shear wall are one of the most commonly used in Multi-Storey buildings for resisting the lateral load. In this paper, the multistorey building is modeled and analyzed by STAAD-Pro Software. Building with shear wall is analyzed using STAAD-Pro software and the comparison is done withmodelwithout shear wall. The main focus on the studies of seismic behavior of shear wall in multi-storey building and it will be discussed in detail. The calculation is done by using the IS Code IS 1893:2002, criteria for earthquake resistant design of structures part 1 general provisions and buildings. And the use of IS456:2000, and IS875:1987also have been done in this paper. The results of Displacements and storey drift havebeen computed in both the cases with and without shear wall in STAAD-Pro by using Response Spectrum Method and areobserved as, buildings, employing shear walls at the exterior corners leads to an impressive 77.28% reduction in displacement, while placing them in the middle of the exterior wall achieves a slightly higher reduction of 77.63%. This emphasizes the effectiveness of shear walls in both configurations, with a marginal advantage for the latter.

Seismic behavior of composite shear walls with post-casting UHPC boundary elements and CRB600H steel bars

This study investigates the seismic behavior of composite shear walls reinforced with post-casting Ultra-High Performance Concrete (UHPC) boundary elements and Colded-Rolled Ribbed Bars (CRB600H). The research aims to explore the synergistic effects of UHPC and CRB600H bars on seismic performance. Six shear wall specimens with a shear span ratio of 1.56 were subjected to cyclic loading to evaluate their failure modes, crack patterns, hysteresis behavior, stiffness degradation, ductility, residual deformation, and energy dissipation capacity. The results demonstrated that the use of CRB600H bars in boundary elements of normal concrete specimens improved post-yield stiffness and reduced residual deformation. Conversely, incorporating UHPC in boundary elements enhanced load-bearing capacity and crack control but slightly reduced ductility due to the weaker interfacial connection between UHPC and the foundation. Additionally, CRB600H bars in the web region improved load-bearing capacity while maintaining ductility comparable to HRB400 bars. The findings suggest that substituting CRB600H for HRB400 in shear-dominant regions can enhance the seismic performance of shear walls. Finally, the multi-layer shell element numerical model validated by the experimental results was encouraged to conduct parametric analysis in the future. This research supports the development of more resilient building structures by integrating high-performance materials in key structural components.

Efficient deep learning based models for rapid prediction of RC shear wall responses under monotonic and cyclic loading

The seismic response of reinforced concrete (RC) shear walls is of paramount importance in earthquake-resistant design. While traditional techniques such as finite-element-based modeling and experimental testing provide comprehensive insights into shear wall behavior, they often require significant computational resources and time. In response, this study investigates the efficacy of various Deep Neural Networks (DNNs), including Convolutional Neural Networks (CNNs), Bidirectional Long Short-Term Memory (Bi-LSTM) networks, and LSTM-Based Autoencoders, in predicting the behavior of RC shear walls under monotonic and cyclic loading conditions. Through training on a diverse dataset encompassing various geometric configurations, material properties, and loading scenarios, the proposed approach generalizes well to unseen cases, enabling rapid estimation of shear wall responses without extensive numerical simulations. This approach offers several advantages, including faster design iterations, improved assessment of existing structures, and potentially higher accuracy. Extensive comparative analyses against experimental tests and numerical simulations evaluate the performance of the deep learning models. Results demonstrate that the proposed approach achieves superior accuracy in prediction of hysteresis and pushover curves, effectively capturing the nonlinear structural behavior of RC shear walls subjected to static and cyclic loading conditions. Validation using a comprehensive experimental database of 160 specimens shows that the model achieves less than 10 % error in maximum lateral load predictions for specimens within the training data range; while simultaneously reducing computational time Overall, this study contributes to the evolving landscape of structural engineering by showcasing the potential of DNNs as efficient tools for predicting the behavior of RC shear walls.

Experimental study to unraveling the seismic behavior of CFRP retrofitting composite coupled shear walls for enhanced resilience

This study focuses on the empirical examination of the nonlinear seismic performance of carbon fiber-reinforced polymer (CFRP)-strengthened composite coupled reinforced concrete (RC) shear walls. The experimental setup involves testing the structure in two distinct states, wherein CFRP sheets are utilized for retrofitting and reinforcement. In the initial phase, three samples undergo reinforcement utilizing distinct patterns of CFRP sheets. In the subsequent stage, an additional trio of specimens is fabricated and tested without the application of CFRP sheets. Subsequently, all structures are exposed to a load equivalent to 60 % of their flexural capacity. Following this, the tested specimens undergo retrofitting with CFRP sheets, utilizing the same patterns as in the initial phase. The retrofitted composite coupled shear walls are then subjected to retesting. The principal aim of CFRP retrofitting is to amplify the flexural and shear capacities of the specimens, empowering them to endure heightened seismic loads in comparison to their original configurations. This research contributes by evaluating ductility, ultimate strength, energy dissipation, and construction costs associated with composite coupled steel plate-concrete shear walls. All specimens underwent cyclic loading in accordance with the ATC-24 guidelines [1], which provide standard protocols for testing the cyclic performance of structural components. These guidelines, outline procedures for simulating seismic loading conditions in laboratory settings to evaluate the performance of structural systems under cyclic loading. Finally, a parametric study explores the impact of CFRP sheets and their adhesion patterns on the seismic behavior of composite coupled shear walls. The selection of the optimal retrofitting scheme considers the construction cost of each specimen based on the total area of CFRP sheets utilized.

Buckling-restrained behavior of woven steel strip shear walls: Experiment and numerical simulation

A novel woven Buckling-Restrained Steel Strip Shear Wall (WBR-SSSW) is proposed for low and medium-rise buildings in this study. The proposed shear wall, comprising inclined arrangements of steel strips with varying dimensions, is categorized into compression and tension steel strips under horizontal loads. By weaving the steel strips, the out-of-plane buckling deformation of the compression strips is significantly alleviated. Cyclic tests were carried out on two 1/3-scaled single-story single-span SSSW specimens to investigate the seismic behavior of woven and non-woven SSSW. Finite element models of two types of SSSW were established and validated by test results. The results showed that the WBR-SSSW exhibited a distinct stress transfer path and stable bearing capacity, with the tension steel strip bearing the majority of the shear load. Compared to specimen SSSW, the WBR-SSSW reduced out-of-plane displacement by over 35 % at each loading level. Parametric analysis of the thickness, number, and width-to-spacing ratios of the steel strips was conducted to optimize the woven-net size. Additionally, a simplified theoretical model for WBR-SSSW was developed, showing good accuracy compared to finite element results, which can be used to estimate the structural shear bearing capacity.

Behavior of Cellulosic Fiber Board Wood-Frame Shear Walls with and without Openings under Cyclical Loading

Behavior of Cellulosic Fiber Board Wood-Frame Shear Walls with and without Openings under Cyclical Loading

Finite Element Modeling and Analysis of RC Shear Walls with Cutting-Out Openings

In recent decades, reinforced concrete (RC) shear walls have been one of the best structural solutions to resist lateral load in high-rise buildings. Shear wall openings are essential for preparations and architectural requirements, which weaken the wall, reducing bearing capacity, energy absorption, and stiffness while also causing stress concentrations. This paper presents a comprehensive finite element (FE) investigation of the behavior and performance of RC shear walls with openings and subjected to lateral loads. The study aims to evaluate the influence of various parameters, such as opening location, size, wall aspect ratio, axial load, and concrete strength, which affect the performance of shear walls. FE models were developed to simulate the seismic response of RC shear walls under the combined effect of constant axial and lateral loads. The obtained results from the FE model showed a successful validation using the experimental data available in the literature. The FE analysis results demonstrate that the inclusion of lower openings leads to a 25% decrease in the bearing capacity of the wall when compared to the upper openings. Moreover, it was observed that augmenting the sizes of the openings and the aspect ratios of the wall resulted in declines in the strength, stiffness, and energy absorption capacity of the wall while simultaneously enhancing the ductility and displacement of the RC shear walls.

Seismic behavior of innovative reinforced concrete composite shear wall with PEC boundary columns

Considering the inadequate integrity between boundary elements and wall connections in shear walls with PEC columns. A new type of PEC shear wall is proposed to enhance the connection between the PEC columns and the wall by introducing T-section connectors to improve the bearing capacity as well as the deformation capacity. In this study, the seismic behavior of composite shear walls was investigated in terms of the failure process, hysteresis, energy consumption, etc. The test results showed that the specimens had good stiffness and energy dissipation capacity. The combination of PEC columns with RC shear walls under the action of the T-section connector was effective. An increase in the width-to-thickness ratio can lead to shear bonding failure. In the PEC-RCSW structure with a shear-to-span ratio of 1.35, the bearing capacity and deformation capacity of the T-section connectors and PEC columns are slightly higher in the major axis direction than in the minor axis direction. Based on the test results, the finite element model was established and further research was conducted on the shear span ratio and T-section connector size. And provided engineering application suggestions for the innovative composite shear wall shear wall. Finally, flexural and shear capacity calculation formulae of the innovative composite shear wall were proposed.

Evaluating the Role of Mortar Composition on the Cyclic Behavior of Unreinforced Masonry Shear Walls.

The mechanical behavior of unreinforced masonry (URM) shear walls under in-plane cyclic loading is crucial for assessing their seismic performance. Although masonry structures have been extensively studied, the specific influence of varying lime content in cement-lime mortars on the cyclic behavior of URM walls has not been adequately explored. This study addresses this gap by experimentally evaluating the effects of three mortar mixes with increasing lime content, 1:0:5, 1:1:6, and 1:2:9 (cement:lime:sand, by volume), on the cyclic performance of brick URM walls. Nine single-leaf wall specimens 900 mm × 900 mm were constructed and subjected to combined vertical compression and horizontal cyclic loading. Key parameters such as drift capacity, stiffness degradation, and energy dissipation were measured. The results indicated that the inclusion of lime leads to a moderate improvement in drift capacity and ductility of the walls, with the 1:1:6 mix showing the highest lateral capacity (0.55 MPa), drift at cracking (0.08%), and drift at peak capacity (0.31%). Stiffness degradation and energy dissipation were found to be comparable across all mortar types. These findings suggest that partial substitution of cement with lime can enhance certain aspects of masonry performance. Further research is recommended to optimize mortar compositions for unreinforced masonry applications.

Study on seismic performance of the CFST-framed aeolian sand concrete composite shear wall

This study examined the seismic performance of composite shear walls framed with concrete-filled steel tubes (CFST) utilizing aeolian sand concrete. Six specimens were designed and tested under low cyclic load with a constant axial compression ratio. The research aimed to analyze how the CFST frame affects the seismic behavior of shear walls made from aeolian sand concrete and understand the underlying influence mechanism. The results showed significant differences in failure modes between CFST-framed and conventional aeolian sand concrete shear walls, with the former exhibiting a lower degree of failure and instances of plastic hinge failure. The hysteretic curve of CFST-framed walls displayed noticeable pinching, indicating enhanced seismic energy dissipation capacity and ductility. The damage analysis model based on the energy damage principle was found to be suitable for conducting seismic damage analysis of these walls. A shear capacity model was also established to accurately depict the variation in bearing capacity under low cyclic loading, providing valuable insights for engineering applications.

Experimental and numerical study on seismic behavior of high energy-consuming resilient concrete shear walls reinforced by CFRP bars and magnetorheological dampers

To achieve the expected seismic properties of high energy consumption and resilience for well used concrete shear walls, the paper presents experimental and numerical study on seismic behavior of concrete shear walls reinforced by carbon fiber-reinforced polymer (CFRP) bars in boundary elements and magnetorheological (MR) dampers. Firstly, a full-scale multi-coil shear valve MR damper was developed and tested under cyclic load to study the effects of current and displacement on the mechanical properties of the MR damper. Then five full-scale cantilever wall specimens reinforced with CFRP bars and MR dampers were tested under reversed cyclic lateral load under different axial load ratios and damping forces. All specimens exhibited significant resilience with little residual drift less than 0.5 %. It was observed that with the increase of axial load ratio, the load-bearing capacity and energy consumption increased, while the ultimate deformation decreased. The load-bearing capacity and energy consumption were improved by increasing the current of the MR damper. Finally, a parallel numerical simulation and parameter analysis were conducted based on a proposed numerical analysis model considering the slippage of CFRP bars. The parameter analysis discussed the effects of the parameters of concrete strength, CFRP bar modulus, steel bar strength, and installation height of MR damper on seismic behavior of the wall.

Hysteretic Behavior of Self-Centering Shear Wall Incorporating Superelastic Shape Memory Alloy Bars and Engineered Cementitious Composites Subjected to Cyclic Loading

Hysteretic Behavior of Self-Centering Shear Wall Incorporating Superelastic Shape Memory Alloy Bars and Engineered Cementitious Composites Subjected to Cyclic Loading

Effect of middle stud on ultimate strength and behavior factor of brick masonry shear wall in cold formed steel frame

AbstractLightweight steel framing is one of the modern construction technology systems. This system is mostly used for low to mid-rise buildings. The lightweight steel framing system has many advantages, including lightness, ease of installation, high execution speed, and being more cost-efficient. Since the manufacturers of cold formed steel frames use bricks in an unprincipled way to cover these structures and because of less laboratory research in this regard, in the present research to principled use of this structure, the effect of the middle stud was evaluated on seismic behavior of brick shear wall in cold formed steel frame with brick face. For this purpose, four cold formed steel frames were made in two different configurations (without middle stud and with middle stud) using cement sand mortar, wire mesh, and brick shear walls. Based on the results, the middle stud would cause weakness in the permissible deformation of the brick walls, and in shear walls without middle stud, deformations occur along with the acquisition of resistance to larger deformations. Accordingly, the presence of the middle stud increases the average shear strength by 30%, and this increase in resistance causes a decrease in the behavior factor and ductility of the walls, which practically indicates the seismic behavior of the frames with the middle stud.

Experimental and numerical study on seismic behavior of shear wall with cast‐in situ concrete infilled walls

AbstractThe shear wall system with cast‐in situ concrete infilled walls has been widely used in high‐rise buildings due to its significant advantages in construction. In this paper, quasi‐static tests were conducted on the shear walls with and without cast‐in situ concrete infilled walls to analyze their failure modes, load‐bearing capacity, stiffness, energy dissipation capacity, and ductility. A simplified model of the shear wall with cast‐in situ concrete infilled walls was proposed based on the fiber element model in OpenSees. The test results showed that the shear wall specimens with cast‐in situ concrete infilled walls exhibited full‐section compression or tension failure, and the cast‐in situ concrete infilled walls did not show obvious damage. Compared with the shear wall without infilled walls, the overall stiffness, load bearing capacity, and energy dissipation capacity of the shear wall specimens with cast‐in situ concrete infilled walls improved, indicating better seismic performance than those without infilled walls. Comparison between the hysteresis and skeleton curves derived from the tests and those simulated by the proposed simplified model revealed errors within 15% for stiffness, yield bearing capacity, and ultimate bearing capacity for shear walls with cast‐in situ concrete infill walls, affirming the effectiveness and accuracy of the model.

CFRP-strengthened shear walls: Combined effects of CFRP and reinforcement ratio

This study presents a three-dimensional numerical model based on the Hashin damage criteria to assess the seismic performance of Carbon Fiber Reinforced Polymer (CFRP)-strengthened Reinforced Concrete (RC) shear walls, accurately capturing the rupture of CFRP strips. The effectiveness of various CFRP-concrete interface modeling methods in capturing CFRP debonding was initially discussed. A series of numerical simulations were then conducted to investigate the combined effects of the CFRP ratio and the horizontal reinforcement ratio on the seismic behavior of CFRP-strengthened shear walls. The results indicate that an increase in the CFRP ratio reduces the failure degree of shear walls, as the shear damage shifts progressively from the concrete and horizontal reinforcement to the CFRP strips. However, an increase in the horizontal reinforcement ratio counterproductively weakens the shear-strengthening effect provided by the CFRP strips. To specifically evaluate the shear contribution of the CFRP strips, a novel coefficient was proposed and validated, capturing the combined effect of the CFRP ratio and the horizontal reinforcement ratio on the shear contribution of the CFRP strips. This coefficient provides a quantitative measure to optimize the reinforcement design of RC shear walls.

Seismic behavior of a hollow precast concrete shear wall with insulation under high axial compression ratios

A hollow precast concrete shear wall (HPCSW) with multiple vertical hollow cores that is advanced in lightweight and thermal insulation is studied in this paper. Novel tapered grouted sleeves (TGSs) are developed to connect the adjacent shear walls, which can avoid grouting defects through visible grouting processes. Seven full-size specimens with an aspect ratio of 3.3, including three solid precast shear walls, three hollow precast shear walls, and a cast-in-place (CIP) shear wall, were subjected to cyclic loading tests, which considered different and high axial compression ratios (ACRs) of 0.3, 0.45, and 0.6. The results show that the solid precast shear wall with the TGS connection displays comparable failure mode and seismic behavior with the CIP one. In contrast, the HPCSW suffers hollow core crushing under high ACRs, leading to a significant reduction in deformation and energy dissipation capacity. Finally, numerical models of HPCSW specimens with different layouts of the hollow cores were established using ABAQUS to evidence the test results and optimize the structure. The results show that the configuration of the outer hollow cores influences the seismic behavior of the HPCSW vastly. It is recommended that the concrete is partially filled into the outer hollow cores to obtain good insulation and seismic capacity simultaneously, with the filling height greater than the predicted crushing height.

Behaviour of a Cold-Formed Steel Shear Wall with Centre-Corrugated Steel Sheathing under Cyclic Loading

A cold-formed steel shear wall with centre-corrugated steel sheathing (CCSS-CFS shear wall) was innovatively developed to meet the requirement of earthquake resistance for multi-rise CFS structures in regions at high seismic risk. This wall exhibits superior seismic performance in comparison with the conventional CFS shear wall. Five full-size specimens were tested under cyclic loading to evaluate their failure mode, shear strength, lateral stiffness, ductility, energy dissipation, as well as degradation of bearing capacity and stiffness. Additionally, the effects of CFS frame structure forms, screw spacing, and corrugated steel sheet thicknesses on the behaviour and failure mechanism of shear walls were analysed. The seismic performance objectives corresponding to intact, slight, moderate, and severe damage were also determined. The results revealed that the main failure modes of shear walls were plastic buckling of corrugated steel sheathing and local buckling of the end composite stud. Optimising configurations such as setting up stiffening plates on the end composite stud, installing transverse braces, and increasing screw spacing between composite studs and sheathing significantly improved their behaviour. The strength of corrugated steel sheathing after plastic buckling should be taken into consideration for the lateral design of the CCSS-CFS shear wall. A calculation method was also proposed in order to determine the elastic global buckling shear strength of the CCSS-CFS shear wall – which exhibited high accuracy. Finally, nominal shear strength, a resistance factor, and a safety factor were recommended.