Steel Plate Shear Wall Systems Research Articles

Mechanical Properties of Semi-Rigid Steel Frame-Braced Steel Plate Shear Wall

Due to mechanical performances of brace and steel plate, mechanical properties of semi-rigid joints and its construction and installation, semi-rigid steel frame-braced steel plate shear wall system is proposed. Nonlinear static analysis with parameters (thickness of plate, type of brace, size of brace and the ratio of span to height) changed of a single-span and single-floor semi-rigid steel frame-braced steel plate shear wall system illustrates that braced steel plate shear walls contributes obviously to bearing capacity and lateral rigidity of semi-rigid steel frame. Also, the finite element analysis (by ANSYS) show that semi-rigid steel frame-braced steel plate shear wall system has excellent ductility.

Comparison of the Progressive Collapse Resistance of Seismically Designed Steel Shear Wall Frames And Special Steel Moment Frames

In this study, the progressive collapse potential of seismically designed steel plate shear wall (SPSW) systems is investigated using the alternate path method, and their performances are compared with those of the conventional special moment frame (SMF) systems. Nonlinear static and dynamic analyses are conducted to follow the progressive collapse of the structures, and their ability of absorbing the destructive effects of member loss is investigated. The obtained results show that when a corner or a middle column in the first story of the SPSWs is removed, the rest of the structure is not able to provide an appropriate alternative path for redistributing the generated loads caused by member loss, and therefore the structure presents a high potential for progressive collapse. However, by changing the lateral load resisting system of these buildings with the SMFs, the progressive collapse resisting capacity of the buildings increases significantly.

Structural performance of unstiffened low yield point steel plate shear walls

Employment of low-yield stress steel plates in shear wall systems has been demonstrated in a number of studies to be a promising alternative for improving the buckling stability, energy absorption capacity, and serviceability of these lateral force-resisting systems, in which material yielding of infill plates may occur either before or after or even at the same time as geometrical buckling. Accordingly, based on their slenderness parameter as well as buckling and yielding behavior, infill plates in steel shear wall systems may be divided into slender, moderate, and stocky categories with respective early buckling, concurrent buckling and yielding, and early yielding characteristics. Such a classification enables the accurate evaluation of buckling and yielding behavior of low yield point steel plate shear walls, which can consequently result in efficient structural and economical design of these lateral force-resisting as well as energy dissipating systems. On this basis, this paper assesses the structural behavior as well as plate–frame interaction characteristics of unstiffened low yield point steel plate shear wall systems via finite element and analytical approaches. Following the experimental validation of the numerical modeling, advantages of use of low yield point steel as compared to the conventional steel are demonstrated. Subsequently, the structural performances of code-designed shear walls with slender, moderate, and stocky low yield point steel infill plates are evaluated comparatively. Finally, the effectiveness of a modified plate–frame interaction (PFI) model in predicting the response of steel shear wall systems with moderate and stocky infill plates is demonstrated.

Development of a simplified equivalent braced frame model for steel plate shear wall systems

Steel Plate Shear Walls (SPSWs) have been accepted widely as an effective lateral load resisting system. For seismic performance evaluation of a multi-story building with SPSWs, detailed finite element models or a strip model can be used to represent the SPSW components. However, such models often require significant effort for tall or medium height buildings. In order to simplify the analysis process, discrete elements for the framing members can be used. This paper presents development of a simplified equivalent braced model to study the behavior of the SPSWs. The proposed model is expected to facilitate a simplification to the structural modeling of large buildings with SPSWs in order to evaluate the seismic performance using regular structural analysis tools. It is observed that the proposed model can capture the global behavior of the structures quite accurately and potentially aid in the performance-based seismic design of SPSW buildings.

Behavior of unstiffened steel plate shear wall with simple beam-to-column connections and flexible boundary elements

This study investigates the effect of type of beam-to-column connections on the overall performance of steel plate shear wall (SPSW) systems under lateral loading condition. An analytical study using finite-element analysis has been conducted on a two-story SPSW system with rigid and pinned beam-to-column connections having constant panel aspect ratio and plate slenderness ratio. All boundary elements are designed as per the current code provisions. The influence of the type of connections between the web plates and the boundary elements on the overall performance of SPSW systems is also studied. In addition, the behavior of SPSW system with flexible boundary members along with pinned beam-to-column connections is also investigated under lateral loading condition. An experimental study has been carried out on a two-story SPSW specimen with flexible boundary elements to investigate its overall performance under the slow-cyclic loading. Based on the analytical and experimental results, various design issues of SPSW systems are discussed.

Seismic design and behavior of low yield point steel plate shear walls

Steel plate shear walls (SPSWs) with low yield point (LYP) steel infill plates have been demonstrated in a number of studies to be efficient and promising lateral force-resisting and energy dissipating systems. In fact, use of LYP steel with extremely low yield stress and high elongation capacity compared to the conventional steel enables the employment of infill plates with improved buckling stability, serviceability, and damping characteristics. In contrast to the commonly-used slender and conventional steel plates with relatively low buckling and high yielding capacities, LYP steel plates can have low yielding and high buckling capacities due to the early yielding of the steel material. On this basis, this paper aims at evaluating the structural behavior and performance of SPSWs with unstiffened LYP steel infill plates designed per AISC 341 seismic provisions which typically address SPSWs with slender infill plates. Effects of plate aspect ratio, and combined compressive and shear forces acting on the web plate are also considered in this study. Numerical analysis of the code-designed LYP steel shear wall models demonstrates the efficient strength, stiffness, and cyclic performances of such systems. In addition, the effectiveness of some design requirements specified in AISC 341 code is evaluated based on the behavior of the SPSW components, and design recommendations are provided accordingly. Finally, a modified plate-frame interaction (PFI) method is used to predict and characterize the behavior of SPSW systems with low yielding and relatively high buckling capacities, the effectiveness of which is verified by comparing the predicted response with experimental and numerical results.

Seismic performance of self-centering steel plate shear walls with beam-only-connected web plates

In the self-centering steel plate shear wall (SC-SPSW) system, thin steel web plates provide the primary lateral strength and energy dissipation, while post-tensioned connections in the boundary frame provide recentering and mitigate frame damage. In most steel plate shear walls (SPSWs), web plates are connected to the beams and columns; however, connecting the web plates to the beams only has been proposed as a means of reducing boundary frame demands and mitigating web plate damage. This paper investigates the impact of using beam-only-connected web plates on SC-SPSW design and seismic performance. Expressions for determining beam demands for purposes of design are developed. Three- and nine-story prototype SC-SPSWs are designed using beam-only-connected web plates and are compared with equivalent SC-SPSWs designs with fully-connected web plates. To evaluate the potential for material savings, the weight of steel required for each system is compared. The seismic performance of the SC-SPSWs with beam-only-connected and fully-connected web plates is compared using results of nonlinear response history analyses in which relatively simple, yet conservative, modeling techniques are employed.

Probabilistic assessment of structures with SPSW systems and LYP steel infill plates using fragility function method

Steel plate shear walls (SPSWs) have been used as primary lateral force-resisting systems in seismic design of new and retrofit of existing buildings. Employment of low yield point (LYP) steel infill plates with considerably low yield strength and high ductility, on the other hand, has been shown in a number of studies to improve the structural performance of SPSW systems. By considering the various sources of randomness and uncertainties involved in the design and retrofit process, adoption of a probabilistic methodology can result in a robust seismic performance assessment of such structural systems. This paper presents the results of a study on the seismic performance and vulnerability of retrofitted structures employing SPSW systems and LYP steel material through probabilistic seismic demand analysis (PSDA). Three 9-story code-designed and retrofitted structural models including a moment-resisting and two SPSW frames are considered. Appropriate seismic response and ground motion intensity parameters, and damage as well as repair states are selected. Structural and nonstructural drift and acceleration fragility functions are subsequently developed based on nonlinear time-history analysis results. The effectiveness of SPSW systems in improving the seismic performance and reducing the vulnerability of buildings is demonstrated through seismic response assessment and fragility analysis. Also, it is shown that employment of relatively thicker LYP steel infill plates in seismic design and retrofit of SPSWs results in smaller damage potential and better seismic performance of such systems.

Buckling and yielding behavior of unstiffened slender, moderate, and stocky low yield point steel plates

Steel plates may be classified as slender, moderate, and stocky based on their distinctive behavior characterized by geometrical buckling and material yielding. Slender plates undergo elastic buckling first and then yield in the post-buckling stage, while stocky plates yield first and then undergo inelastic buckling. Moderate plates, on the other hand, buckle and yield simultaneously. The development of low yield point (LYP) steel enables the application of steel plates with improved buckling and energy absorption capacities as lateral force-resisting and energy dissipating elements in structures. On this basis, buckling and yielding behavior of LYP steel plates with various support and loading conditions is studied in this paper from the point of view of their application in steel plate shear wall (SPSW) systems. The limiting thicknesses of standalone plates corresponding to concurrent geometrical buckling and material yielding are determined theoretically and verified through detailed numerical simulations. Effects of using LYP steel and plate aspect ratio parameter on the required limiting plate thickness as an effective parameter in seismic design of SPSW systems are investigated as well. In addition to the studies on the performance of plates with two and four restrained edges and also applicability of some extrapolation techniques for predicting the critical buckling load of moderate plates, detailed studies are performed on determination of the limiting plate thickness in code-designed SPSW systems. Based on the findings of this study, some practical recommendations are provided for efficient seismic design of SPSW systems with LYP steel infill plates.

Performance assessment of steel plate shear walls under accidental blast loads

Previous research on properly-designed steel plate shear wall systems has proven that it has a high level of lateral shear strength and stiffness and large ductility. These properties, along with ample redundancy, robustness, and superior energy dissipation capacity under severe cyclic loading, have made the system a viable lateral force resisting system for seismically-active regions. Although similar properties are desirable for protective structures, their application in this regard has been largely neglected. The potential application of some form of the steel plate shear wall as a protective system in industrial plants possibly subjected to accidental explosions is studied by means of iso-response curves. To capture all important aspects in blast response, a comprehensive numerical model is developed. The constitutive model for the steel material includes mixed-hardening, strain-rate effects, and damage initiation and evolution. The pressure–impulse diagrams for both in-plane and out-of-plane blast orientations, along with the corresponding weight–standoff distance diagrams, are produced with the aid of the numerical model. Different response criteria and wall sizes are considered. A method is proposed to produce dimensionless iso-response curves to broaden their applicability. The results show that despite the inherent slenderness of the steel members, the wall system has the potential to be an effective system for use in a protective structure for industrial plants, especially for the in-plane blast load condition.

Behavioral characteristics of code designed steel plate shear wall systems

A series of code designed steel plate shear walls (SPSWs) with different aspect ratios and number of stories are numerically analyzed to investigate different aspects of the behavior of such SPSWs, particularly with regard to the wall/frame contributions. Results show that frames contribute effectively in resisting story shear only at a few of lower stories and infill plates absorb substantial part of story shear at the remaining stories. About 70–80% of the compressive column axial force comes from plate tension fields. The tensile column is found to be more effective in resisting base shear than the compressive one and it contributes about 55–95% of the total shear force of the frame column bases at the ultimate state. Up to 32% reduction in the overall stiffness of SPSWs due to early buckling of their infill plates is observed. The first yield points in the infill walls and in the boundary frames of different SPSWs occur at about 25–45% and 70–85% of their strength, respectively. As a result of the current design procedure that neglects the boundary frame moment resisting action, the stiffness and ductility of SPSWs having almost the same design lateral loads but different aspect ratios can be quite different.

The wall–frame interaction effect in steel plate shear wall systems

The overall behavior of steel plate shear wall (SPSW) dual systems comprises the contributions of the infill plate tension field and boundary frame moment resisting actions. In the literature, a moment frame acting as SPSW boundaries (SPSW boundary frame) is treated as the same frame acting alone (bare frame). However, due to an interaction effect between the infill wall and the boundary frame, the actual behavior of SPSW boundary frame is different from the behavior of the same bare frame. In the present paper, a number of code designed single and multi-story SPSWs and the corresponding bare frames are numerically analyzed (a) to study the influence of infill walls on the behavior of boundary frames and (b) to evaluate the effectiveness of infill walls. Results show that the presence of infill walls can significantly improve the performance of moment-resisting frame systems, especially for multi-story ones, in terms of strength, stiffness, ductility and energy dissipation capability. In turn, the better performance of the SPSW system than the corresponding bare frame is not only due to the contribution of the infill wall, but also due to the improvement in the performance of the frame resulted from the wall–frame interaction.

Lateral stiffness of steel plate shear walls

The steel plate shear wall system has been used in a number of buildings as an innovative lateral force resistant system. Openings often exist in the steel plate shear walls due to the various functional requirements of structures. These openings may negatively impact the lateral stiffness of steel plate shear walls. Therefore, an experimental research was instituted to investigate the seismic behavior of steel plate shear walls, with and without openings. The experimental results showed that steel plate shear walls have the satisfying seismic behavior, and, as expected, the strength and stiffness characteristics of the walls were reduced due to openings. Then a single-story wall panel FE model and an analytical deep beam model are developed in order to find the critical factors dominating the thickness reduction coefficient of wall panels with the opening. Furthermore, extensive parametric analysis is conducted to derive a simplified formula for the determination of the thickness reduction coefficient of wall panels with the opening for substituting solid wall panels with reduced thickness for actual wall panels with the opening. Finally, the design method for calculating the lateral stiffness is verified by some experimental programs and recommended for the routine practice of steel plate shear walls.

Analysis of composite steel plate shear walls connected with frame beams only

A composite steel plate shear wall system consists of a steel plate shear wall with reinforced concrete panels attached to one side or both sides by bolts or connectors. This arrangement restrains the possible occurrence of out-of-plane buckling of thin-walled steel plate, thus significantly increasing the load-carrying capacity and ductility of the overall wall. Experimental studies on composite steel plate shear walls and steel plate shear walls connected with frame beams were carried out. The experimental results illustrated the good ductility and excellent energy dissipation capacity of composite steel plate shear walls. The load-carrying capacity and energy dissipation capacity of steel plate shear walls clearly increased compared with those of steel plate shear walls. Meanwhile, a finite-element model was developed to analyse the behaviour of steel plate shear walls and composite steel plate shear walls, and its accuracy was validated by making comparisons with the experimental results. Based on the finite-element analysis results, a simplified model of steel plate shear walls was proposed, and it is suggested that this can be used in the analysis of shear wall systems in high-rise buildings.

Performance-based plastic design of steel plate shear walls

The existing codes and design guidelines for steel plate shear walls (SPSWs) fail to utilise the excellent ductility capacity of SPSW systems to its fullest extent, because these methods do not consider the inelastic displacement demand or ductility demand as their design objective. A performance-based plastic design method for SPSW systems with rigid beam-to-column connections is proposed in this work, which sets a specific ductility demand and a preferred yield mechanism as its performance targets. The effectiveness of the proposed method in achieving these targets is illustrated through sample case studies of four- and eight-storey SPSW systems for varied design scenarios. A comparison with the existing AISC method for the same design scenario shows that the proposed method consistently performs better, in achieving these performance-based targets. The proposed method is modified to account for P-Delta effects, wherever necessary. This modified method is found to be more effective than the original proposal, whenever P-Delta effects are significant.

New Finite Element for Steel Shear Plate Analysis

AbstractA new rectangular orthotropic finite element including drilling rotations and nonnodal degrees of freedom for plane stress analysis is developed, and is fully compatible with a refined frame element; therefore, the membrane and the frame actions are coupled. This plane stress element in combination with a refined beam-column element can accurately model steel plate shear wall (SPSW) systems. The stresses and displacements obtained from numerical examples demonstrate the good accuracy and performance due to the combination of both elements when modeling SPSW with only one plane stress element between the building floors instead of using a dense mesh; therefore, an easier output is obtained to provide a final detailed design. This refined plane stress element provides another analytical tool for practicing structural engineers for the analysis of SPSW. The thin web infill plate design is based on the shear demand obtained directly from the analysis.

Lateral resistance capacity of stiffened steel plate shear walls

The steel plate shear wall system has been used in a number of buildings as an innovative lateral force resistance system. Stiffened steel plate shear walls possess greater stability and energy absorption during dynamic loading, such as during seismic loading, when compared with unstiffened steel plate shear walls. Openings, however, often exist in the steel plate shear walls due to various functional requirements of the structure. These openings may negatively impact the overall capacity of the shear wall, necessitating additional stiffening. Therefore, an experimental research program was instituted to investigate the seismic behavior of stiffened steel plate shear walls, with and without openings. Strength, stiffness, ductility and energy absorption were evaluated based on the results of reversed cyclic loading tests on three specimens. Two of the test walls had openings, while one wall was constructed without any openings. The test program results showed that stiffened steel plate shear walls exhibit satisfactory seismic behavior, and, as expected, the strength and stiffness characteristics of the walls were reduced in walls with openings. In addition to the test program, an analytical study utilizing a beam–shell mixed Finite Element (FE) model of a single-story wall panel with boundary columns is made to determine the critical factors influencing the shear strength reduction of stiffened wall panels with the opening. Furthermore, extensive numerical calculation and parametric analysis are conducted to derive a simplified formula for the determination of the shear strength reduction coefficient. In addition, complex elasto–plastic FE models of the three specimens are developed to investigate in detail the lateral force resistance behavior of stiffened steel plate shear walls. Good agreement is observed between the experimental and numerical results. Finally, a design method for calculating the lateral resistance capacity, based on the test program and the FE model analysis, is recommended to be used for the routine design practice of stiffened steel plate shear walls.

Strip Angle Changes in Accordance with the Deformation Mode of Seismic Steel Plate Shear Wall Systems

This study investigated the tension-field action induced strip angle changes and deformed mode shapes of SPSW for high-rise structures subjected to lateral forces. Based on the numerical analysis 3, 9, 14 and 20 story structures, shear and flexural modes were identified by comparing the numerical analysis results to the predicted strength by theory. Shear deformation mode exhibited a constant angle in tension-field; whereas, flexural mode of the numerical results, differed from the tension-field action theory.

Probabilistic evaluation of effect of column stiffness on seismic performance of steel plate shear walls

The lateral force resistance and hysteretic energy dissipation capacity of steel plate shear walls (SPSWs) are primarily provided through yielding of the infill steel plates attached to the boundary frame of the system. As such, it is desirable to achieve uniform distribution of infill plate yielding at every story of an SPSW system during an earthquake event. This paper investigates the effect of column stiffness on infill plate yielding distributions in representative two-story and six-story SPSWs. Specially considered in the investigation are the uncertainties existing in infill plate strength and lateral force distributions along the vertical direction. Three probabilistic evaluation methods including the Monte Carlo method, the Latin Hypercube Sampling method, and the Rosenblueth’s 2K+1 Point Estimate method, are considered. It is shown that all methods are stable and effective for this investigation; however, the Rosenblueth’s 2K+1 Point Estimate method requires the least computational cost. The results from the probabilistic evaluation show that increasing column stiffness and story ductility capacity can be effective to achieve infill plate yielding at each story of an SPSW. However, the minimum column stiffness required in the codes in North America does not necessarily lead to infill plate yielding at every story of a multi-story SPSW.

SEISMIC LATERAL FORCE DISTRIBUTION FOR DUCTILITY-BASED DESIGN OF STEEL PLATE SHEAR WALLS

The thin unstiffened steel plate shear wall (SPSW) system has now emerged as a promising lateral load resisting system. Considering performance-based design requirements, a ductility-based design was recently proposed for SPSW systems. It was felt that a detailed and closer look into the aspect of seismic lateral force distribution was necessary in this method. An investigation toward finding a suitable lateral force distribution for ductility-based design of SPSW is presented in this paper. The investigation is based on trial designs for a variety of scenarios where five common lateral force distributions are considered. The effectiveness of an assumed trial distribution is measured primarily on the basis of how closely the design achieves the target ductility ratio, which is measured in terms of the roof displacement. All trial distributions are found to be almost equally effective. Therefore, the use of any commonly adopted lateral force distribution is recommended for plastic design of SPSW systems.