Unstiffened Steel Plate Shear Walls Research Articles

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.

Analytical Study on the Strengthened Steel Plate Shear Walls by FRP Laminate

In this paper, nonlinear behaviour of composited steel plate shear walls by means of glass fiber reinforced polymer (GFRP) laminates under quasi-static loading have been analytically investigated. In that regard, numbers of the tested ½ scaled one-story un-stiffened steel plate shear walls (SPSWs) have been selected and simulated using finite element method, based on the available experimental data in the literature. After calibration of the analytical models, numbers of GFRP layers are added to the steel web plates of SPSWs, and effects of GFRP laminate and the number of layers on the seismic behaviour of steel shear walls are investigated. The results indicate that GFRP laminate increase the ultimate shear capacities of SPSWs, and the secant shear stiffness of the system. Besides, the hysteretic behaviour of the composite steel shear walls have been improved in comparison with the un-stiffened steel shear walls.

Stiffness and strength degradation of steel shear walls having an arbitrarily-located opening

Openings in steel plate shear walls (SPSWs) in buildings are provided for architectural reasons as well as for access requirements. Despite the reduction of stiffness and strength in panels with an opening being well-understood, further studies are essential in order to determine both the mechanism and the degree of this degradation, as well as its dependency on the location and the size of the opening. To accomplish this aim, a non-linear finite element analysis is used in this paper to study the behaviour of both stiffened and unstiffened SPSWs with a single rectangular opening. The size and location of the opening are varied from model to model in order to determine their influences on the stiffness and strength of the system. Based on the results obtained, the strength and stiffness degradation of unstiffened panels are affected adversely by the location of the opening. In contrast, the re-location of an opening of a specific size within the panel area in stiffened panels does not appear to influence this degradation, so that the stiffness and strength deterioration are not a function of the location of the opening. As expected, both stiffened and unstiffened panels experience a progressive reduction in their stiffness and strength with an increase of the size of the opening. It is demonstrated further that with an increase in the opening ratio (width to height), the energy absorbed by the system arising from seismic loading considerations in both stiffened and unstiffened SPSWs show a linearly decreasing trend; this trend being less stiff for stiffened panels. Unstiffened SPSWs with a central opening experience the least energy absorption. It is also shown that the absorption of energy is substantially higher in stiffened panels when compared with their otherwise identical, but unstiffened, counterparts.

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.

Comparing Steel Plate Shear Wall Behavior with Simple and Corrugated Plates

Experimental and numerical studies conducted in the past three decades have demonstrated that a steel plate shear wall is an effective and economical lateral load resisting system against both wind and earthquake forces. The system consists of infill steel plates connected to boundary beams and columns over the full height of the framed bay. The infill plates can be stiffened or unstiffened and the beam-to-column connections can be rigid or shear connections. A properly designed steel plate shear wall has superior ductility, high initial stiffness, stable hysteresis loops, and good energy absorption capacity. These characteristics make the system outstanding in high-risk seismic regions. Use of steel plate shear wall systems has been shown to be more cost effective than the other lateral load resisting systems. Steel plate shear walls are much lighter than the commonly used reinforced concrete shear walls, which reduce both the gravity loads and seismic forces. This aspect significantly reduces the foundation costs and makes the system outstanding for application in rehabilitation projects. Whereas construction cost of stiffened steel plate shear wall is more than unstiffened steel plate shear wall therefore in this investigation the unstiffened steel plate shear wall has been studied as two types of simple and corrugated plate and the behavior has been compared in one story frame. This study was conducted with finite element approach theoretically. The results of this study demonstrated that behavior of corrugated plate is superior to simple plate because it has high loading capacity, ductility and energy absorption.

The Analysis of Lateral Displacement Target of Unstiffened Steel Plate Shear Wall Based on the Performance Designing

A typical three-story unstiffened Steel Plate Shear Wall (SPSW) finite element model was established. Systematic parameters analysis of the development and changing process of the lateral stiffness and shear capacity was mainly carried on the middle standard layer. The result shows that the lateral stiffness of thin SPSW has been always in decline and has a higher shear capacity after buckling. According to lots of analysis data and different stages of lateral control targets in the new revised seismic design code for performance designing, the lateral limits of the SPSW were respectively qualified under wind loads and frequent earthquake.The test verification was also proposed to verify the restrictive lateral limits so as to supply a scientific basis for the preparation of SPSW design method.

Tall building with steel plate shear walls subject to load reversal

SUMMARYThis paper presents a state‐of‐the‐art review of research on thin unstiffened steel plate shear walls including recent research advances, in addition to a case study building that used them as the primary lateral‐force‐resisting system. Thin unstiffened steel plate shear walls are becoming an attractive alternative to traditional lateral‐force‐resistance systems because they exhibit desirable structural properties. A properly designed steel plate shear wall will have considerable energy dissipation capacity, ductility, initial stiffness and ultimate strength. Furthermore, the said walls are efficient in terms of cost and space due to their light weight, ease of construction and small footprint. The case study building is a 55‐story high‐rise system that took advantage of these properties. Details are presented regarding the design process and tools that were used to ensure a safe and efficient structure. Copyright © 2011 John Wiley & Sons, Ltd.

Stiffness and Strength Of Perforated Steel Plate Shear Wall

Steel Plate Shear Walls (SPSW) have been used as a lateral-load-resisting system in buildings. With formation of tension fields, unstiffened SPSW possesses good ductility and high energy dissipating capability under cyclic loading. However, large demand is induced to the frame members from panel yielding. For typical frame configurations, very thin panels are often required to limit such demand but sometimes result in construction difficulties. This paper attempts to reduce such demand by introducing perforations to thicker panels. The effect on stiffness and strength is investigated through nonlinear finite element technique. Based on results described in this paper a simple linear reduction function is proposed.

Beam‐attached steel plate shear walls

SUMMARYConnecting to their surrounding beams and columns, unstiffened steel plate shear walls (SPSWs) are widely used as an appropriate lateral resisting system for designing and retrofitting of structures against lateral loads. The base philosophy for the performance of such systems, post‐buckling tension field formation, needs strong enough boundary elements to form. However, in some cases, relatively low performance demand needs panels with impractical thickness. To overcome the construction limitations, the designer is forced to use thicker plates, and consequently to satisfy the post‐buckling tension field philosophy, heavier column sections must be used. A novel configuration of steel shear walls, beam‐attached SPSWs, in which the size of the column section is released to be as a function of the plate thickness and removes the wasteful need for heavy columns, is proposed in this paper. Copyright © 2010 John Wiley & Sons, Ltd.

Analysis of Steel Plate Shear Walls Using the Modified Strip Model

Unstiffened steel plate shear walls are an effective and economical method of resisting lateral forces on structures due to wind and earthquakes. Structural engineers require the ability to assess the inelastic structural response of steel plate shear walls using conventional analysis software that is commonly available and is relatively simple and expeditious to use. The strip model, a widely accepted analytical tool for steel plate shear wall analysis, is refined based on phenomena observed during loading of steel plate shear walls in the laboratory. Since the original strip model was proposed as an elastic analysis tool, these refinements are made primarily to achieve an accurate representation of yielding and eventual deterioration of the wall, although moderate improvements in initial stiffness predictions are also made. In assessing each of the proposed refinements, modeling efficiency is evaluated against the accuracy of the solution. A parametric study using the modified strip model examines the effect of varying the angle of inclination of the tension strips on the predicted inelastic behavior of the model. Notably, it was found that the ultimate capacities of steel plate shear wall models with a wide variety of configurations vary little with the variation of the inclination of the strips.

Design of steel plate shear walls considering inelastic drift demand

The unstiffened steel plate shear wall (SPSW) system has emerged as a promising lateral load resisting system in recent years. However, seismic code provisions for these systems are still based on elastic force-based design methodologies. Considering the ever-increasing demands of efficient and reliable design procedures, a shift towards performance-based seismic design (PBSD) procedure is proposed in this work. The proposed PBSD procedure for SPSW systems is based on a target inelastic drift and pre-selected yield mechanism. This design procedure is simple, yet it aims at an advanced design criterion. The proposed procedure is tested on a four-story test building with different steel panel aspect ratios for different target drifts under selected strong motion scenarios. The designs are checked under the selected ground motion scenarios through nonlinear response-history analyses. The actual inelastic drift demands are found to be close to the selected target drifts. In addition, the displacement profiles at peak responses are also compared with the selected yield mechanism. Future modifications required for this design procedure for different SPSW configurations are identified based on these test cases.

A numerical study on response modification, overstrength, and displacement amplification factors for steel plate shear wall systems

AbstractDesign recommendations for steel plate shear wall (SPSW) systems have recently been introduced into seismic provisions for steel buildings. Response modification (R), overstrength (Ωo), and displacement amplification (Cd) factors for SPSW systems presented in design codes were based on professional experience and judgment. A numerical study has been undertaken to evaluate these factors for SPSW systems. Forty‐four unstiffened SPSW possessing different geometrical characteristics were designed based on the recommendations given in the AISC Seismic Provisions. Bay width, number of stories, story mass, and steel plate thickness were considered as the prime variables that influence the response. Twenty records were selected to include the variability in ground motion characteristics. In order to provide a detailed analysis of the post‐buckling response, three‐dimensional finite element analyses were conducted for the 44 structures subjected to the selected suite of earthquake records. For each structure and earthquake record, two analyses were conducted in which the first includes geometrical nonlinearities and the other includes both geometrical and material nonlinearities, resulting in a total of 1760 time history analyses. In this paper, the details of the design and analysis methodology are given. Based on the analysis results, response modification (R), overstrength (Ωo), and displacement amplification (Cd) factors for SPSW systems are evaluated. Copyright © 2008 John Wiley & Sons, Ltd.

Closure to “Unstiffened Steel Plate Shear Wall Performance under Cyclic Loading” by Adam S. Lubell, Helmut G. L. Prion, Carlos E. Ventura, and Mahmoud Rezai

Closure to “Unstiffened Steel Plate Shear Wall Performance under Cyclic Loading” by Adam S. Lubell, Helmut G. L. Prion, Carlos E. Ventura, and Mahmoud Rezai

Connection of infill panels in steel plate shear walls

The behaviour under cyclic loading of unstiffened steel plate shear wall panels at their connection to the bounding beams and columns was investigated on full-size panel corner details. Four different infill panel connection details were tested to examine and compare their response to quasi-static cyclic loading. The load versus displacement response of the details showed gradual and stable deterioration at higher loads. The formation of tears in the connection details did not result in a loss of load-carrying capacity. In addition to the experimental program, a finite element model was developed to model the behaviour of one of the infill plate corner connection specimens. Results from the analysis showed that the finite element method can be used to obtain the load versus displacement behaviour of an infill panel-to-boundary member arrangement.Key words: cyclic loading, hysteresis, shear wall, steel, welded connection.