Steel Shear Walls Research Articles

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.

Seismic experiment and performance analysis on embedded optimized steel plate-reinforced concrete composite shear wall under multi-dimensional loading

In order to investigate the seismic performance of reinforced concrete shear walls under multi-dimensional loading mode and its effect on performance improvement, an embedded optimized steel plate-reinforced concrete composite shear wall is proposed. Based on the design principle that the shear wall could adequately bear multi-dimensional loading and the embedded steel plate could reach the full stress state, the X-shaped optimized steel plate (for in-plane loading mode) and the triangular optimized steel plate (for out-of-plane loading mode) are determined using different optimization methods. The combination scheme of these two plates is utilized in the oblique loading mode. Quasi-static loading tests are conducted on eight typical shear wall specimens, and performance parameters such as hysteresis curve, skeleton curve, ductility, stiffness degradation, strain evolution, and damage evaluation of the specimens are compared and analyzed. In addition, variable parameter analysis is performed using finite element software to compare the strain distribution state of each steel plate. The results indicate that the embedded optimized steel plate-reinforced concrete composite shear wall structure exhibits higher bearing capacity, greater deformation capacity, and superior energy dissipation capacity under different loading angles compared to the tradition reinforced concrete shear walls. This composite structure can provide greater lateral stiffness, and the optimized steel plate can reach the full stress state at all loading angles, effectively reducing the damage of steel bars and concrete. These findings offer a foundation for the study of seismic performance and performance improvement methods for shear wall structures under multi-dimensional earthquake action.

Experimental evaluation of cyclic behavior of precast concrete frame with steel shear wall

AbstractThis study seeks to integrate steel shear walls with precast concrete systems into stable and resistant structures against lateral loads. It is desired to study the ductility factor, lateral strength, and behavior as well as the energy absorption of this integrated system compared to the precast concrete frame without a shear wall. For this purpose, two steel shear wall samples made of mild steel and galvanized steel plates are constructed within a precast concrete frame. The assembly is tested under a cyclic lateral load. The integrity of the connections of steel strips of the wall together, and the boundary of the wall to the frame, is observed to be excellent. The main failure mode is composed of the diagonal yielding of the steel wall. The system benefits from large hysteresis loops and no degradation because of any instability. The beam‐column connections remain almost intact even at large cycles of deformation. Moreover, a bare precast concrete frame is tested in the same way to compare the lateral behavior. The utilized ductile beam‐column connections are successful in retaining the integrity of the system until large drifts. However, the seismic design characteristics of the bare frame turn out to be inferior to the steel shear wall system. Results of the cyclic tests show that by proper design of the interior and exterior connections of the shear wall as well as the beam‐column connections, the steel shear wall system can largely increase the stiffness, ultimate strength, and energy dissipation capacity of a bare precast moment resisting reinforced concrete frame. On top of that, the system is able to retain its integrity up to lateral drifts over 2%.

Seismic design rules for lightweight steel shear walls with wood panel sheathing within the Eurocode format

Within the 2nd-generation of Eurocodes several new lateral force resisting systems (LFRS) typically used in lightweight cold-formed steel (CFS) buildings have been introduced, including shear walls with wood sheathing (SWWS). Therefore, extensive studies have been carried out to define the seismic design parameters according to the format of European code for seismic design, i.e. Eurocode 8. In current version of the 2nd-generation Eurocode 8 (prEN1998-1-2, CEN 2022), in case of SWWS the behaviour factor has been defined based on the FEMA P695 (FEMA, 2009) [3] methodology, whereas the other seismic design parameters have been set based on assumption validated with analyses on limited case studies. To overcome this lack, specific research devoted to defining the main seismic design parameters for SWWS belonging to Ductility class 3 (DC3) according to prEN1998-1-2 (CEN 2022) has been carried out at the University of Naples “Federico II”. The research shows that the Easley et al. (1982) method gives consistent in-plane horizontal wall resistance predictions if the shear resistance of wood panel-to-steel sheet screw connections (sheathing connections) is evaluated with reliable approaches and formulas for the evaluation of the shear resistance of sheathing connections have been calibrated. Based on the results obtained from this research, a partial safety factor for resistance evaluation of SWWS according to limit state design (LSD) equal to 1.3 is proposed and an overstrength (expected resistance) factor for the design of non-ductile elements according to capacity design equal to 1.7 is recommended.

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.

Effect of corrugated plate arrangements on the performance of steel shear wall frames

Nowadays, the use of corrugated steel shear walls with sinusoidal, triangular, and trapezoidal profiles, which are stiffened steel walls without stiffener, is recommended for delaying the premature occurrence of buckling in the plate. The arrangement of corrugated plates in the structural frame alters seismic parameters; therefore, this research focuses on various arrangements of inclined corrugated plates. For this purpose, experimental specimens are first validated under cyclic quasi-static loading using ABAQUS finite element software. Subsequently, the design of four different arrangements of inclined corrugated plates with three profiles of trapezoidal, sinusoidal, and triangular is conducted and compared with vertical and horizontal arrangements. Based on the results, the triangular waveform demonstrated better energy absorption, initial stiffness, and ultimate strength. Investigation of different plate thicknesses for triangularly corrugated shear walls, including 0.75, 1.25, and 1.75 mm, showed that increasing the wall thickness improved the seismic behavior. Additionally, Arrangement No. 1 (inclined arrangement) provided the highest energy absorption and ultimate strength; however, its behavior in the hysteresis curve was asymmetric. This issue has been addressed by implementing a double arrangement of plates.

Investigating the influences of the geometry and orientation of corrugation in the steel shear walls on the cyclic behavior through the use of finite element analysis

To dampen the loading sequences in the constructions, using the shear walls is recommended. Shear walls, which withstand the lateral forces (i.e., parallel to the plane of the wall) of wind and seismic activity, prevent buildings from collapsing while columns and load-bearing walls support the structure’s compression load all the way to the foundation. Besides, some new techniques are innovated for strengthening the structure like outrigger system. The steel shear walls are mostly used in the steel structures due to their high strength, ductility, and low weight. Recently, implementing Corrugated Steel Shear Walls (CSSWs) has gained more attention because they can absorb much amount of energy compared to flat steel shear walls. There are two important parameters in the CSSWs that play crucial roles in controlling their strength; corrugation geometry and orientation. Therefore, the current research paper aims to study numerically the effects of four corrugation geometries (trapezoidal, square, zigzag, and curved) with two orientations on the cyclic behavior of the CSSWs. Finite Element Analysis (FEA) is used to simulate the seismic loading conditions and finally, this procedure is validated through the comparison of the modeled flat shear wall with the experimentally published results. The difference between the peak loads of hysteresis curves obtained numerically and experimentally is about 8.5%. The stated FEA procedure in this paper can be regenerated by other researchers. The results confirmed the applicability of the CSSWs compared to the flat shear walls. Also, the vertical corrugation infill patterns result in higher strength in comparison to the horizontal ones. For instance, in the zigzag and square corrugation shapes, the plastic energy dissipation of the vertically oriented specimens (13.84 and 14.01 KJ, respectively) is higher around 7% and 29%, respectively than the horizontally oriented ones (12.9 and 10.84 KJ, respectively). Besides, the trapezoidal and curved corrugation geometries show the highest cumulated energy and plastic energy dissipation.

Investigating The Behavior Of Reinforced Concrete Frame With Steel Shear Wall Having Partial Connection To Boundary Elements

Investigating The Behavior Of Reinforced Concrete Frame With Steel Shear Wall Having Partial Connection To Boundary Elements

Seismic performance of various types of cold-formed steel composite shear walls with CFRP-toughened screw connections

The cracking of screw connections at the corners of wallboards is a typical failure mode for cold-formed steel (CFS) shear walls, resulting in premature performance degradation of CFS structures. A toughening method with carbon fiber reinforced polymer (CFRP) sheets at screw connection locations is proposed for strengthening the CFS shear walls. Totally 6 full-scale CFS shear walls with or without CFRP-toughened connections were tested, and the parameters of the lamination scheme, wallboard type and screw distance were investigated. A numerical model is developed for simulating the seismic behaviour of the tested specimens, and a theoretical model for predicting their shear strength is proposed. Results showed that the shear strength and lateral stiffness of the CFS walls with CFRP-toughened screw connections increased by more than 30 %, and the continuous lamination scheme provided greater strength. The fastener-based numerical model could effectively be used for predicting the hysteretic performance of toughened CFS shear walls well; both the pinch behaviour and ultimate strength are predicted well, and it can be used as an effective tool for the seismic design of toughened CFS shear walls with a theoretical model.

Structural Performances of Steel Shear Walls with Different Web-Plate Corrugation Patterns

Structural Performances of Steel Shear Walls with Different Web-Plate Corrugation Patterns

Topology optimization of the flat steel shear wall based on the volume constraint and strain energy assumptions under the seismic loading conditions

In structural engineering systems, shear walls are two-dimensional vertical elements designed to endure lateral forces acting in-plane, most frequently seismic and wind loads. Shear walls come in a variety of materials and are typically found in high-rise structures. Because steel shear walls are lighter, more ductile, and stronger than other concrete shear walls, they are advised for usage in steel constructions. It is important to remember that the steel shear wall has an infill plate, which can be produced in a variety of forms. The critical zones in flat steel shear walls are the joints and corners where the infill plate and frame meet. The flat infill plate can be modified to improve the strength and weight performance of the steel shear walls. One of these procedures is Topology Optimization (TO) and this method can reduce the weight and also, increase the strength against the cyclic loading sequences. In the current research paper, the TO of the infill steel plate was considered based on the two methods of volume constraint and maximization of strain energy. Four different volumes (i.e., 60%, 70%, 80%, and 90%) were assumed for the mentioned element in the steel shear wall. The obtained results revealed that the topology configuration of CCSSW with 90% volume constraint presented the highest seismic loading performance. The cumulated energy for this type of SSW was around 700 kJ while it was around 600 kJ for other topology optimization configurations.

A Review on Slit Steel Shear Walls: Development, Implementation, and Performance

Over centuries, natural phenomena have claimed a large number of lives and caused large amounts of damage. However, they were the reason for the development of knowledge and science. In engineering, there is no doubt that earthquakes were the driving force behind many design philosophies and advanced technologies. In this regard, steel plate shear walls (SPSWs) represent one of the technologies employed in both new constructions and existing structures to bolster lateral load resistance. In addition to its high elastic stiffness and strength, SPSWs often experience significant pinching during their hysteretic response unless heavily stiffened. Thus, numerous investigations have been performed recently to enhance the seismic behavior of SPSWs during severe ground shaking. The shear walls of steel plates have been studied in various ways, including stiffened and unstiffened steel plates, low yield strength steel plates, SPSWs perforated with circular holes or vertical slits, steel walls with stiffened and unstiffened openings. A stiffened SPSW panel dissipates significantly more energy than an unstiffened panel, as well as exhibiting a ductile and stable behavior. In view of its high elongation, the SPSW with low yield point has the best damping capacity. It has been demonstrated that steel walls perforated with circular holes have improved energy dissipation, in addition to allowing utilities to pass through their openings. Vertical slits on steel plate shear walls produce an exceptionally full hysteresis loop with improved performances. Slit steel walls (SSWs) can sustain a drift of over 3% while experiencing minimal hysteresis degradation. Additionally, a frame with a SSW can endure up to 6% drift without significant damage, surpassing expected ductility levels of a special moment frame, particularly with efficient slit geometry.

Investigating the behavior of a steel shear wall consisting of a corrugated and flat plate with fully and semi connections to boundary elements

Investigating the behavior of a steel shear wall consisting of a corrugated and flat plate with fully and semi connections to boundary elements

Numerical comparison of truss-shaped lateral load-resisting systems with conventional steel shear walls

Steel plate shear wall (SPSW) is considered to be one of the most efficient lateral load-resisting systems. However, this system has some drawbacks, including the difficulty of construction, installation challenges, and potential serviceability issues. Although many studies have been conducted to enhance the seismic performance of SPSWs, these systems have not gained widespread popularity due to their cost and time-consuming installation process. In this study, an innovative structural system called truss-shaped lateral load resisting system (TS-LLRS) is developed and proposed as an alternative to SPSWs to address these challenges and provide architectural advantages. The TS-LLRS is composed of steel elements arranged in the configuration of a 2D truss, connected to the boundary elements within a frame rather than a thin plate. First, a numerical study is performed using five finite element models. The generated models with different arrangements were analyzed and compared with SPSWs regarding structural characteristics such as stiffness, energy dissipation, ultimate strength, and stress distribution. Next, a parametric study was conducted using 64 TS-LLRS finite element models with different arrangements. Two key parameters controlling the behavior of TS-LLRSs were the angle and slenderness ratio of the truss elements. The optimum angle of the truss elements was found to be approximately 45 degrees. Finally, a case study was conducted using a 9-story building. The results demonstrated that TS-LLRS exhibited desirable behavior, which was relatively similar to SPSWs, indicating its potential as an alternative to steel plate shear walls. Additionally, a tentative value of 6.5 has been proposed for the response modification factor of TS-LLRS.

Seismic performance of cold-formed steel shear walls with a shear plate of low-yield steel

A novel cold-formed steel (CFS) sheathed and bare shear walls with a low-yield steel shear energy-dissipating plate is proposed by taking advantage of the plastic deformation generated by the shear plates to reduce the damage of CFS shear walls under earthquake. In this paper, the seismic performance of six CFS shear walls with shear plates using low-yield steel is experimentally studied through full-scale cyclic tests. Different configurations of energy dissipation segments and the replacement of the energy-dissipating shear plate after the earthquake (through two walls) are investigated. A list of influencing parameters on the performance of the shear walls is studied including the fixed conditions of the specimens, the type of built-up studs, the rigidity and strength of the shear plates, and the connection method between the shear plates and the walls. Overall, within a certain lateral displacement level, the damage of the shear wall is concentrated in the energy dissipation segment. The shear plate reaches the plastic stage before the CFS frame as designed. Meanwhile, the mechanical performance of repaired structures with the shear plate replacement after the earthquake is maintained well.

Seismic performance and risk mitigation of CFS shear walls with CFRP-reinforced screw connections and special-shape L-section end studs

Cracking damage of screw connections and buckling of end studs always resulted in performance degradation of cold-formed steel (CFS) shear walls. To improve the seismic performance and to avoid the brittle failure of CFS shear walls, two methods for strengthening CFS walls are proposed in this paper: carbon fiber reinforced plastic (CFRP) toughened screw connections (CFRP-SC) and special-shape built-up end studs with L-shaped sections (SBC-L). A total of 5 full-scale strengthened CFS walls with CFRP-SC or SBC-L were tested to examine the performance, and simplified numerical models of strengthened CFS walls and 5-story CFS buildings were developed and validated. Nonlinear dynamic analyses are performed to investigate the effects of those two methods on seismic responses and risks of CFS buildings, and the risk mitigation of CFS buildings is then discussed. The results show that the CFS shear walls with CFRP-SC can mitigate the damage to screw connections and wallboards nearby those connections, especially for the connections at the corners of the walls. The connections could continually dissipate the earthquake energy due to large loading and deformation capacities. The SBC-L can effectively delay the buckling failure of end studs, thus enhancing the shear resistance of CFS walls. Due to the two methods, the collapse probability of the CFS building with CFRP-SC in service life is reduced by almost 40.8%, and that of the building with CFRP-SC and SBC-L is reduced by almost 59.7%.

Shear performance of cold-formed steel shear walls reinforced by moment frame

A novel hybrid structural system consisting of a steel frame and cold-formed steel shear wall has been proposed. The cyclic test was conducted to investigate the impact of the steel frame, sheathing, and opening on the seismic performance of specimens. Furthermore, numerical models were created and validated using experimental data, and the reinforcement of the frame was studied in greater detail. The results indicate that: 1. The steel frame significantly contributes to the preservation of the framing's integrity even after damage to the sheathing. 2. Despite failure, the specimens still retain over 70% of their shear strength when subjected to a large drift ratio of 1/20 rad. 3. The simulated results show good agreement with the experimental results, and the numerical models accurately predict the shear performance of the system.

Nonlinear Dynamic Behavior of Semi-Supported Steel Shear Walls

Despite the many advantages of steel shear walls, such as high strength and stiffness, good ductility and high energy dissipation, the increase in the size of columns next to the steel shear walls is a drawback that affects the use of this system. In order to achieve an economic design while keeping design essentials and optimal performance, a novel steel shear wall system called “semi-supported steel shear wall (SSSW)” was proposed, in which the wall plate is attached to the secondary columns instead of the primary columns of the frame. The secondary columns are only responsible for creating the tension field in the plate and the lateral load rather than partnership in the toleration of gravity loads. In this paper, due to the lack of knowledge on the dynamic behavior of steel plate shear walls in general and SSSW in particular, the nonlinear dynamic behavior of SSSWs is investigated. The explicit finite element method is used for analysis and the results are verified by the laboratory test results. The results of the nonlinear dynamic analysis show that semi-supported shear walls have a very good dynamic performance in increasing stiffness and reducing the lateral displacement of the structure. The effects of various parameters of SSSW on its dynamic behavior are also investigated.

Machine learning-based prediction of hysteretic behaviors of two-side clamped steel shear walls

This study proposes a methodology that can construct the hysteretic curves of two-side clamped steel shear walls (TCSSWs) using a machine learning technology to address the inherent deficiencies of multivariable regression analysis which has been typically used for developing the hysteretic model of a common structural element. A deep neural network (DNN) is adopted for this study and a new architecture is proposed by modifying numbers of neurons and hidden layers to well capture the cyclic response of TCSSWs. Using a training datasets DNN architectures with several combinations of input parameters and configurations relating to numbers of neurons and hidden layers had been trained. This study considers a total of 70 DNN architectures and selects the best-fitting DNN architecture which produces the minimum mean-square-error value. Estimates from the proposed DNN architecture are evaluated with a test dataset and their accuracy is acceptable. Finally, the selected DNN architecture is further verified with a validation dataset consisting of TCSSWs with different material properties of steel. The modeling parameters for the hysteretic curves of TCSSWs can be properly captured by the proposed DNN architecture.

Parametric study on seismic response modification factor of strap-braced cold-formed steel systems

While cold-formed steel structures have been extensively studied for seismic-resistant construction, existing regulations, and implementation guidelines do not comprehensively address the impact of key design parameters on the seismic behavior of CFS strap-braced shear wall systems. This study investigates the lateral resistance and seismic behavior factor of strap-braced shear walls and compares them with code values, and tries to fully understand the effect of different design parameters on the seismic R-factor of these systems. The effect of parameters such as the strap cross-sectional area, aspect ratio, and distance between the studs is studied using ANSYS finite element software to create datasets for various configurations. The pushover analysis results obtained from this analysis are utilized to perform incremental dynamic analysis, under a set of 22 ground motion records, to evaluate the seismic response modification factor for different residential buildings. For this purpose, one to four-story residential buildings are designed based on four seismic hazard zones: low, moderate, high, and very high and then, they are analyzed. Results of pushover analysis show that increasing the strap cross-sectional area and aspect ratio increases capacity, but changing the distance between studs does not have a significant effect, and the R factor presented by codes is conservative. Incremental dynamic analysis results also indicate that the behavior of studied buildings varies depending on the structure and selected record and the suggested R factor by codes for diagonal straps braced cold-formed steel structures is acceptable for buildings up to three stories in low, medium, and high seismic zones, and for buildings up to two stories in very high seismic zones. Overall, this study shows that strap-braced cold-formed steel shear walls have the potential to achieve higher seismic R-values in comparison to design codes.