Infill Plate Research Articles

Stress state of steel plate shear walls under compression–shear combination load

SummaryThis paper investigates the stress state of the infill steel plate for the unstiffened steel plate shear walls (SPSWs) under compression–shear combination load. First, the infill steel plate is divided into three zones, the stress state of each zone under compression is derived, and the accuracy of the analytical model is verified by a series of numerical examples. Second, considering the combination effects of the gravity load and shear force from the adjacent boundary columns, the stress state of each zone is proposed and discussed. Then the shear capacity of the infill steel plate for the unstiffened SPSWs with gravity load acting on the top of the boundary columns is proposed. Finally, the shear capacity of 21 numerical SPSW specimens with various axial stresses of the boundary columns and different steel infill plate thicknesses is predicted.

Seismic upgrading of reinforced concrete frames with steel plate shear walls

The objective of this paper is to report on a study of the use of unstiffened thin steel plate shear walls (SPSWs) for the seismic performance improvement of reinforced concrete frames with deficient lateral rigidity. The behaviour of reinforced concrete frames during seismic activities was rehabilitated with an alternative and occupant-friendly retrofitting scheme. The study involved tests of eight 1/3 scale, one bay, two storey test specimens under cyclic quasi-static lateral loadings. The first specimen, tested in previous test program, was a reference specimen, and in seven other specimens, steel infill plates were used to replace the conventional infill brick or the concrete panels. The identification of the load-deformation characteristics, the determination of the level of improvement in the overall strength, and the elastic post-buckling stiffness were the main issues investigated during the quasi-static test program. With the introduction of the SPSWs, it was observed that the strength, stiffness and energy absorption capacities were significantly improved. It was also observed that the experimental hysteresis curves were stable, and the composite systems showed excellent energy dissipation capacities due to the formation of a diagonal tension field action along with a diagonal compression buckling of the infill plates.

11.24: Impact of column flexural stiffness on behaviour of steel plate shear walls

ABSTRACTIn the past 40 years steel plate shear walls (SPSW) have seen increased application as vertical stabilization systems of structures. Steel plate shear walls (SPSW) may be considered as vertically installed cantilever composed of boundary frame elements (beams and columns) and very slender steel infill panel. In the past, the loss of stability of the infill plate was prevented by adding vertical and horizontal stiffeners, while the present application relies on post‐critical tension field action of the infill panel. For cost‐effective implementation of steel plate shear wall (SPSW) systems the infill steel panel needs to be completely utilized through ability of tension field formation over the entire steel plate. Due to such load bearing mechanism additional transverse forces are exerted on boundary frame members. Hence, in order to ensure expansion of the tension field throughout the entire infill panel the required minimal flexural stiffness of boundary frame element cross‐section shall be met. This requirement is based on assumptions valid for plate girders, where previous studies, indicate that for steel plate shear walls (SPSW) this requirement could be conservative or even completely unnecessary.This paper presents the results of experimental and numerical research. Laboratory testing included two different specimen groups. In order to determine the influence of the infill panel on the behaviour of moment resisting frame (MRF) three steel moment resisting frame (MRF) specimens were tested in the first group, while experiments of the second group included three steel plate shear wall (SPSW) specimens. In each specimen group flexural stiffness of the boundary columns was varied. Experimental results show that steel plate shear wall (SPSW) specimens whose boundary columns do not meet the required minimal flexural stiffness exhibited small “pull‐in” of their columns. Furthermore, the experimental data was used to calibrate numerical models that have been used for additional parametric numerical analyses. Specifically, the influences of three column flexural stiffness values as well as two steel grades of the infill panel were investigated for five different aspect ratio (L/H) values. Impact of the above parameters was assessed through comparison of residual relative horizontal displacement profiles.

11.41: Numerical investigation of influence of plate yield point on performance of steel plate shear wall

ABSTRACTSteel plate shear walls (SPSW) consist of thin infill steel plates attached to beams and columns in steel frames. SPSW are efficient lateral load resisting systems and can act as an alternative to traditional systems. In this study, the nonlinear response of single‐story single‐bay SPSW models having different yield points of infill plates (100, 180, 250 MPa.), were numerically investigated under lateral loading. The other variables in the analysis were the aspect ratio of panels (2 and 2.5), and thickness of the steel plates (3, 5 and 7 mm.). The models were designed according to the “AISC Steel Design Guide 20” and the “AISC 341–10 Provisions”. Finite element models of SPSWs were developed and analysed using ABAQUS nonlinear program. The results show that, using low yield point steel leads to more ductility and with some consideration influence the stiffness of models.

Numerical study of seismic behavior of Composite Steel Plate Shear Walls with flat and corrugated plates

Composite Steel Plate Shear Wall (CSPSW) is a resistant system to lateral forces with suitable performance which can be utilized by corrugated trapezoidal plates enhancing the stiffness of shear wall. In this study, when the space between the corrugations of trapezoidal plates is either filled or empty, the deformability, stiffness and other seismic parameters of Composite Steel Plate Shear Wall have been studied by Abaqus software. The use of CSPSW with corrugated trapezoidal plate with horizontal and vertical corrugations when the space between the corrugations of Infill plate and concrete layer is empty exhibits more deformability as compared to just the same system when the space has been filled with concrete layer. In fact, applying this application detail in CSPSW with corrugated trapezoidal plate is believed to improve the behavior of this lateral resistant system. If we use trapezoidal plate in CSPSW, it would be recommended that the space between corrugations and concrete layer to be empty.

Seismic retrofit of slab-on-girder steel bridges

Thin steel infill plate has been proposed in the past as a ductile end diaphragm to reduce the transverse seismic demand in slab-on-girder steel bridges. However, a simplified method is required to promote the use of steel infill plate end diaphragms as a retrofit strategy. In this paper, the retrofitting strategy is based on the ductility reduction factor (Rμ) provided by the addition of steel infill plate. A step-by-step procedure is developed to calculate the ductility reduction factor which reduces the force demand on vulnerable substructure elements. In addition, this procedure is shown to give results that compare well with numerical data from finite-element analysis.

Cyclic tests of steel plate shear walls using box‐shape vertical boundary elements with or without infill concrete

SummaryThe steel plate shear wall (SPSW) is an effective lateral force resisting system in which unstiffened steel infill plates are connected to the horizontal and vertical boundary elements (VBEs) on all sides of the plates. The boundary elements must be designed to resist the tension field force of the infill panels. When the VBEs are made from a steel box section, the flange of each box VBE connected with the infill panels can be pulled out‐of‐plane by significant panel forces, called pull‐out action. This study investigates capacity design methods for box VBEs in SPSWs. Simplified fixed beam and portal frame models aim to estimate the pull‐out responses of the flange of the box sections with and without infill concrete, respectively. In this study, cyclic tests of three full‐scale two‐story SPSWs using box VBEs with or without the infill concrete are conducted. Inelastic pushover analyses of the finite element models are conducted. The tests and analytical results confirm that the proposed design methods, which aimed to prevent the full yield of the flange under the pull‐out action, are applicable. Furthermore, the test and analytical results suggest that the initial yielding of the flange of box VBEs under the collective effects of the pull‐out action on the flange, the gravity load, and the sway action on the SPSW represents a local yielding. A strict prohibition of the initial yielding on the flange under the aforementioned collective effects is not recommended for pursuing a cost‐effective design. Copyright © 2017 John Wiley & Sons, Ltd.

Performance-Based Plastic Design of Moment Frame-Steel Plate Shear Wall as a Dual System

Steel Plate Shear Wall (SPSW) is an emerging seismic load-resistant system that, compared to other systems, enjoys the advantages of stable ductile behavior, fewer detailing requirements, rapid constructability, and economy. American seismic provisions decree that a SPSW should be designed as a moment frame with a web infill plate. Specifically, in case of buildings taller than 160 ft, it decrees that a dual system must be used. This paper presents a method of Performance-Based Plastic Design (PBPD) to design steel moment frame-SPSW as a dual lateral load-resisting system. PBPD method uses pre-selected target drift and yield mechanism as its main criteria. For a specified hazard level, the design base shear is calculated based on energy work balance method, employing pre-selected target drift. Plastic design of dual frame system has been performed to meet the pre-selected yield mechanism. As presented in the paper, design procedure involves solving a system of five equations with five variables to determine the proportion of SPSW and moment frame shear, shear wall thickness, and beam/ column sections. It has been considered that a four-story structure is designed with the proposed method. Seismic performance of this dual frame system, designed with the proposed method, is evaluated by nonlinear static and dynamic analysis for both Design Basis Earthquake (DBE) and Maximum Credible Earthquake (MCE). Result analysis is in accord with the assumptions, satisfying all the performance objectives. PBPD is a direct design method in which no iteration is needed to achieve the performance objectives. Determining the proportion of SPSW and moment frame shear is an exclusive capability of this procedure.

Boundary frame contribution in coupled and uncoupled steel plate shear walls

SummaryThe steel plate shear wall (SPSW) system is a robust option for earthquake resistance due to the strength, stiffness, ductility and energy dissipation that it provides. Although thin infill plates are efficient for resisting lateral loads, boundary frames that are proportioned based on capacity design requirements add significant structural weight that appears to be one of the factors limiting the use of the system in practice. An alternate configuration, the SPSW with coupling (SPSW‐WC), was explored recently as an option for increasing architectural flexibility while also improving overall system economy and seismic performance. The SPSW‐WC, which extensively employs flexural boundary frame contribution, has shown promise in analytical, numerical and experimental studies, but recent research on uncoupled SPSWs suggests that boundary frame contribution should not be considered for carrying seismic design shear. As a result, in the present study, boundary frame contribution in SPSWs was explored with detailed three‐dimensional finite element models, which were validated against large‐scale SPSW‐WC tests. Six‐story systems were considered, and the study matrix included single and double uncoupled SPSWs along with coupled SPSWs that had various degrees of coupling. Variations in design methodology were also explored. The modeling framework was employed to conduct static monotonic and cyclic pushover analyses and dynamic response history analysis. These analyses demonstrate the beneficial effect of coupling in SPSWs and illustrate the need to consider boundary frame contribution in design of coupled SPSWs. In addition, sharing design shear between the infill plate and the boundary frame is more generally shown to not be detrimental if this sharing is done in the design stage based on elastic analysis and the resulting boundary frame provides adequate secondary strength and stiffness following infill plate yielding. Copyright © 2017 John Wiley & Sons, Ltd.

Seismic behavior of Self-Buckling-Restrained Steel Plate Shear Wall made by two incline-slotted infill plates

This paper presented seismic behavior of a novel Self-Buckling-Restrained (SBR) Steel Plate Shear Wall (SPSW) that was made by two Incline-Slotted Infill Plates (ISIPs) which were tied together by one rubber plate. The directions of the incline slots on the two ISIPs were opposite. Stable cycling responses of the SBR-SPSW could be achieved since at least incline strips on one plate were in tension under the cycle load. At the same time, the strips in tension could provide lateral support to those in compression on the other plate. Behaviors of the SPSW with two ISIPs and with one Solid Infill Plate (SIP) were compared to show advantages of the proposed SBR-SPSW. The stress state changed from the tension-compression bi-direction stress state in a SIP to uniaxial tension or compression in an ISIP. The cracks that usually encountered in a solid steel infill plate under repeated shear buckling could be avoided. And the incline steel strips yielded sequentially that could provide energy dissipation capacity at small drift ratio. At the same time, the ISIP could always ensure the plate yield prior to the frame yield. Parameters of ISIP, including the infill plate thickness, the strips width and the slot width, were investigated through finite element analyses. Shear strengths of the SPSW with two ISIPs decreased with the increase in slot width and increased with the increase in strip width. Design recommendation for the SBR-SPSW was provided as results of theoretical and numerical analysis. The shear strength of the SBR-SPSW made by two ISIPs could be calculated by simplified theoretical equations on the safe side.

Behavior of semi-supported steel shear walls: Experimental and numerical simulations

This paper presents an experimental and numerical study of semi-supported steel plate shear walls which are connected to frame beams and a pair of secondary columns. As the infill plates are not connected to the frame primary columns, the large stresses due to tension field, causing the formation of plastic hinges in the primary columns, are avoided. In order to intensively investigate the structural mechanism of this new type of shear walls, eight specimens were tested under reversed cyclic lateral load. The effects of four perforation diameters as well as two slenderness ratios of infill plates on the seismic behavior of SSSWs were studied experimentally and numerically. All the specimens exhibited satisfactory cyclic inelastic and energy dissipation, thereby indicating an alternative to traditional steel shear walls. Based on the test results, the strength, stiffness, ductility factor and energy absorption characteristics of the specimens were substantially reduced in specimens with openings. Maximum strength reduction, stiffness loss and ductility deterioration in the perforated specimens were 42%, 61%, and 33%, respectively. Deteriorating pinched hysteresis was observed due to the occurrence of cyclic out-of-plane buckling and tension field action. In addition to the test program, complex elastoplastic FE models of the eight specimens were developed to investigate in detail the cyclic behavior of semi-supported steel plate shear walls. Excellent agreement was observed between the experimental and numerical results.

Testing of steel plate shear walls with composite columns and infill plates connected to beams only

This paper focuses on a new type of Steel Plate Shear Walls (SPSWs) consisting of Concrete Filled Steel Tube (CFST) columns and infill plates connected to beams only. To evaluate seismic behavior of such a SPSW system, this research team conducted an experimental investigation on three two-story specimens. The specimens were varied to compare performances of the systems consisting of conventional infill plates permitting buckling and infill plates restrained by reinforced concrete panels for prevention of plate buckling. Test results revealed that a system with buckling restrained infill plates tends to have a higher strength but lower ductility than the one having conventional infill plates with similar geometries and material properties. Moreover, hysteretic energy dissipation feature remains the same in the specimens with buckling restrained infill plates regardless of infill plate dimensions and plate edge boundary conditions. Overall, the new SPSWs with conventional infill plates and buckling restrained infill plates both exhibited stable hysteretic responses and acceptable ductility under cyclic loading; hence, they are recommended for future practice.

Hysteretic behavior of perforated steel plate shear walls with beam-only connected infill plates

The steel plate shear wall with beam-only connected infill plate (SSW-BO) is an innovative lateral load resisting system consisting of infill plates connected to surrounding beams and separated from the main columns. In this research, the effects of perforation diameter as well as slenderness ratios of infill plates on the hysteresis behavior of SSW-BO systems were studied experimentally. Experimental testing is performed on eight one-sixth scaled one-story SSW-BO specimens with two plate thicknesses and four different circular opening ratios at the center of the panels under fully reversed cyclic quasi-static loading in compliance with the SAC test protocol. Strength, stiffness, ductility and energy absorption were evaluated based on the hysteresis loops. It is found that the systems exhibited stable hysteretic behavior during testing until significant damage in the connection of infill plates to surrounding beams at large drifts. It is also seen that pinching occurred in the hysteresis loops, since the hinge type connections were used as boundaries at four corners of surrounding frames. The strength and initial stiffness degradation of the perforated specimens containing opening ratio of 0.36 compared to the solid one is in the range of 20% to 30% and 40% to 50%, respectively.

Investigation Effect of Type, Property and Dimension of Stiffener Perforated Steel Shear Wall

Steel plate shear wall (SPSW) according extra ductility and high strength and lateral stiffness and improved behavior in plastic stage recognized as a good lateral system for building structure, particularly as it interests with earthquake resistant design. Improvise of opening is one advantage of this system. The researchers on perforated steel plate shear wall have shown that the shear strength and stiffness of an un-stiffened steel shear wall decrease due to perforation of the infill plate. So stiffener leads to increasing stability of structural system of buckling and strength, lateral stiffness. To this research still plate shear wall with opening that can be of different material such as rebar, steel plate also effect of increase and decrease of steel plate section area and effect of its dimension studied. Analysis result was observed that applying steel plate with similar area, leads to more ultimate strength. In additionally ultimate strength increase when area increased. With comparing of result of stiffeners dimension due maximum ultimate shear strength. Finally suggest optimum aspect ratio (b/t).

Developing of steel plate shear walls braced with slidable multiple X-shaped restrainers: Hysteretic analyses and design recommendations

This paper proposed a light-weight buckling restrained steel plate shear wall (XSPSW) to improve the earthquake energy dissipation of unstiffened steel plate shear walls. It consisted of two slidable multiple X-shaped restrainers placed on the either side of a steel infill plate. The two restrainers could continue to provide out-of-plane restraint for infill plates to achieve stable energy dissipating capacity under cyclic reversal loads. Theoretical analyses and numerical simulating analyses have been conducted to investigate the hysteretic behaviors of XSPSWs and the stability of their sub-plates. Based on the analysis results, it could be concluded that the proposed XSPSWs were efficient lateral-load resisting members for the buildings in high seismic regions.

Numerical Study on Steel Shear Walls with Sinusoidal Corrugated Plates

Over the past decades a growing demand and interest has stimulated many researchers to investigate different aspects of steel plate shear walls (SPSWs). The structural performance of steel shear walls with sinusoidal corrugated plate infills is investigated in this study. Finite element (FE) analysis was adopted using ANSYS software, wherein flat and corrugatedshear walls - with different thicknesses, various corrugation numbers and angles - were modeled under monotonic and cyclic loads. Results and findings of this study indicate that geometrical variations developed through corrugation can be effective on the capacity, rigidity, and post-yielding responses of such corrugated-web lateral force-resisting systems. In addition, proper design and detailing can result in desirable structural behavior and seismic performance of SPSWs with sinusoidal corrugated infill plates.

Estimation of lateral force contribution of boundary elements in steel plate shear wall systems

SummarySteel plate shear walls (SPSWs) are used as lateral force‐resisting systems in new and retrofitted structures in high‐seismic regions. Various international codes recommend the design of SPSWs assuming the entire lateral load to be resisted by the infill plates. Such a design procedure results in significant overstrength leading to uneconomical and inefficient use of materials. This study is focused on the estimation of contribution of boundary elements in resisting the lateral force considering their interaction with the web plates of SPSW systems. Initially, the relative contribution of web plates and boundary frames is computed for a single‐bay single‐story frame with varying rigidity and end connections of boundary elements. Nonlinear static analyses are carried out for the analytical models in OpenSees platform to quantify this contribution. Later, this study is extended to the code‐based designed three‐story, six‐story, and nine‐story SPSWs of varying aspect ratios. Based on the results obtained, a new design procedure is proposed taking the lateral strengths of the boundary frames into account. Nonlinear time‐history analyses are conducted for 40 recorded ground motions representing the design basis earthquake and maximum considered earthquake hazard levels to compare the interstory and residual drift response and yield mechanisms of SPSWs designed as per current practice and the proposed methodology. Finally, an expression has been proposed to predict the lateral force contribution of the infill plate and the boundary frame of SPSWs. Copyright © 2016 John Wiley & Sons, Ltd.

Experimental testing on CFRP strengthened thin steel plates under shear loading

This paper presents an experimental study on thin steel plates strengthened by CFRP layers under shear loading. A series of laboratory tests were conducted on scaled one-story steel shear panel models with hinge type connections under cyclic quasi-static loading. One of the specimens is un-stiffened and selected as a reference sample of three others specimens. Steel infill plates are strengthened by CFRP layers with different numbers of layers and orientations. The results indicate that the strengthening of thin steel plate by CFRP layers increases ultimate strength, secant stiffness and energy absorption. Comparisons are made between the performance of CFRP and GFRP strengthened steel plates under cyclic shear loads. It was shown that both materials were effective at increasing stiffness and strength of the system. The increased ratio is similar for both FRPs when two layers are applied. However, adding additional two layers of CFRP does not provide extra benefit in terms of stiffness and energy absorption although there is still benefit for ultimate strength.

Structural performance of steel plate shear walls with trapezoidal corrugations and centrally-placed square perforations

Steel plate shear walls (SPSWs) are an efficient lateral force-resisting system, and can be designed with corrugated and/or perforated infill plates, depending on structural considerations, architectural requirements, and service design. This paper presents a study on the structural performance of SPSWs with horizontal trapezoidal corrugations and centrally-placed square perforations under monotonic loading. Finite element models were developed for assessment of the buckling stability, stiffness, strength, and ductility performances of the shear walls. To this end, parametric studies were performed by considering the web-plate corrugation angle, thickness, and size of opening as the varying parameters in the nonlinear pushover analyses. It was found that the design of the boundary frame members can be effective in minimizing the deformations imposed by infill plates, providing system ductility, and developing lateral load resistance through stable development of diagonal tension-field action in the web plate. The effects of introducing web-plate perforations, and increasing the size of the opening, on the structural performance were also investigated. Proper design and detailing of the SPSW, along with optimal selection of the web-plate geometrical and corrugation parameters, can ensure desirable structural behavior and seismic performance for such lateral force-resisting systems.

A Comparative Study of the Shell Element and Strip Model Methods for Analysis of Steel Plate Shear Wall Structures

Shell element and strip model are the two available numerical methods in the analysis of steel plate shear wall (SPSW) structures. The shell element model provides excellent prediction of the behavior of SPSWs. However, when the number of elements increases, especially in high-rise frames, the method becomes time consuming and produces convergence complications. In such cases, the strip model is commonly used as an alternative method. In the literature, the evaluation of the strip model has only been carried out for up to four-story SPSW structures. In the present study, fourteen low- to high-rise SPSW frames having 4, 7, 10 and 13 stories with different bay widths of 2, 3, 6 and 9m are designed and modeled using shell element and strip methods. The pushover analysis results show that the accuracy of strip model is affected by the number of story levels as well as the bay width. The use of beam element in modeling frame members is shown to have considerable effects on the results of the strip model. The panel zones should be modeled as effectively rigid regions in the strip model; and the slenderness ratio of frame members should be considered. It is also found that the distribution of story shear between infill plates and frame members are quite different in the two modeling methods. Furthermore, modifications to improve the accuracy of the strip model are recommended in this paper.