COMPOSITE Steel PLATE SHEAR WALLs (C.S.S.W.) have been used in structures as a lateral resisting system that it's building by concrete cover on one or both sides of steel PLATE. This system that identified as the 3rd version of the SHEAR WALLs, by increasing of stiffness, ductility & energy absorption is widely used in tall building, retrofitting of structures and tanks.In this paper, evaluation of concrete layer to steel PLATE thickness ratio has been investigated on C.S.S.W. behavior. In this regard, some experimental and analytical specimens involved of flexible steel tram, steel SHEAR WALL & steel PLATE SHEAR WALL COMPOSITEd with reinforced concrete layer are built and tested using a rigid frame and actuator. The variable parameters on COMPOSITE SHEAR WALL were the number of concrete layer, distance between stuts and ratio of steel PLATE to of concrete layer thickness. The results show that the stiffness of COMPOSITE SHEAR WALL has direct proportion to concrete layer thickness and has inverse proportion to distance between stuts. Increasing on proportion of thickness of steel PLATE to thickness of concrete layer until optimum thickness reduced the displacement of out of PLATE and beyond which there would be no merit. On the other hand, usage of two concrete layers on two side of steel PLATE was reduced effect of secondary bending.

The steel SHEAR WALL and COMPOSITE steel PLATE SHEAR WALL is introduced in recent three decade and is considered and is spread rapidly. COMPOSITE steel PLATE SHEAR WALL which is made of a layer of thin steel sheet with coating of reinforced concrete in one or both sides of steel palate is considered a third generation of resistance SHEAR WALLs against lateral loads that in addition to increasing the strength, ductility and energy absorption, it is very economical and affordable and it is used in constructing high buildings, retrofitting buildings and tanks. In this paper we have tried to examine the seismic behavior of steel and COMPOSITE SHEAR WALLs. For this purpose several models of steel SHEAR and COMPOSITE WALLs from one to five stories were constructed and analyzed by Abaqus software. The result show that COMPOSITE steel PLATE SHEAR WALLs has more ability to absorb energy, spread produced stress to different parts of the steel PLATE and ductile than steel SHEAR WALLs. The curve hysteresis loop of COMPOSITE steel palate SHEAR WALLs is more stable and sustainable than steel SHEAR WALL. With increasing the number of stories, the initial strength and stiffness is decreased due to increase in lateral shift but the amount of absorbing energy and ductility is increased. The force tolerance in COMPOSITE steel PLATE SHEAR WALL models is increased in comparison with steel SHEAR WALLs.

COMPOSITE couple beams are the concrete elements consisting of longitudinal bars and steel PLATE, therefore suitable for SHEAR transferring in couple SHEAR WALLs with arranged gates in its height. In this paper, after modeling couple beams with and without steel PLATEs with F.E methods and calibration the models with experimental results, effects of parameters such as thickness, height, length and yielding strength of the steel PLATEs located in concrete couple COMPOSITE beam have been investigated on the ductility, energy dissipation and capacity. The results were illustrated that if the PLATE thickness would be increased by four times, ductility and energy dissipation capacity were decreased 15.6 and 14.7 percent and also loading capacity was enhanced up to 25 percent, respectively. And also the PLATE height and length didn’t have influence on above mentioned parameters. Furthermore, by 80 and 280 percent enhancement in yielding PLATE strength, ductility and energy dissipation capacity were decline 10.8 to 23.9 and 8.9 to 21.7 percent and also 19, 33 percent enhancement in loading capacity was happened.

Due to architectural, mechanical and even structural considerations, in some cases there is need to create some openings in the COMPOSITE steel SHEAR WALLs. Presence of the openings can considerably affect the WALL behavior. Therefore, in this study, the effects of the opening on the behavior of COMPOSITE steel SHEAR WALLs are investigated. For this purpose, first an experimental specimen without opening is developed and tested. The outcomes of the experimental study are verified by existing data Then three series of the CSPSW specimens (four specimens in each series) with opening are built and tested. Accuracy and precision of these experimental outcomes is verified by twelve numerical models which are developed using ABAQUS software. Therefore, general behavior of the CSPSWs with opening are investigated according to the attained outcomes from numerical and experimental tests. In addition, some methods are proposed to reduce the negative effects of the opening on the behavior of CSPSW. Then a parametric study is performed to evaluate effects of different parameters namely concrete cover thickness, steel PLATE thickness, thickness of the strengthening PLATE installed around the opening and bolt spacing on general behavior of the CSPSW. In addition to study the effects of opening in behavior of CSPSW, in this paper a thorough investigation about the influence of different parameters on drift of the system is performed. Finally, a formula is proposed based on the developed numerical models to compute lateral displacements of the COMPOSITE SHEAR WALLs with openings. This formula can be utilized for deriving an intensification factor which can be applied to calculate displacement of the COMPOSITE SHEAR WALL with openings from the responses of a WALL without openings.

This paper presents a new configuration for semi-supported steel PLATE SHEAR WALLs to increase their efficiency. For this purpose, the infill steel PLATE is proposed to be a trapezoidal shape instead of a rectangular one. To find the most efficient inclination angle of lateral sides, a numerical parametric study was conducted. Five different values of inclination angle including 60, 75, 90, 105, and 120 degrees were considered. Furthermore, two thicknesses of 1.75 and 2.00 mm were considered for the steel PLATE. The area of the steel PLATE was the same for all the models. The models were analyzed using finite element software ABAQUS. Both geometric and material nonlinearity have been considered. To validate the finite element modeling, the available experimental results were used. According to the results, comparing to the WALL with rectangular PLATE, the inclination angle of 60° increases the ultimate lateral strength and stiffness of the 1.75 mm-thick WALLs by 46% and 66%, respectively. Furthermore, a simple approximate model is presented to calculate the load-deformation response of the proposed WALL using SAP 2000 program. Despite the simplicity of the method, the results were in good agreement with the results of ABAQUS.

This Paper is prepared to provide the state of the art of the seismic behavior as well as seismic design of steel SHEAR WALLs. This Paper contains a summary of the behavior of steel SHEAR WALLs under cyclic load as well as during post earthquakes. Later, one and four stories panel with and without stiffeners is studied. For this purpose, various models of such WALLs are analyzed and modeled. The Result shows that ductility of the system at Nonlinear Zone is increasing and the steel PLATE -against the steel frame- has nonlinear behavior. Also, lateral drift at the steel SHEAR WALL with stiffener is decreasing but lateral drift of the four stories panel at middle beams level is increasing at compared with the non stiffener WALL.

In the last few decades, steel PLATE SHEAR WALLs have been introduced as primary lateral load resisting elements in several buildings around the world. The system consists of vertical steel infill PLATEs, one story high and one bay wide connected to the surrounding beams and columns. Experimental testing was conducted on various specimens, under cyclic quasi-static loading. Good energy dissipation and ductility capacities were achieved. In this concept, the post-buckling strength of the none-stiffened thin steel PLATE SHEAR WALL is relied upon for most of the frame SHEAR resistance, similar to the slender web of PLATE girder. In this paper, a nonlinear finite element model that includes both geometric and material nonlinearity for steel PLATE SHEAR WALLs was developed. Another analytical method is presented that is useful for the prediction of cyclic monotonic behavior. The models gave good prediction of the specimen behavior. In order to understanding the behavior of steel PLATE SHEAR WALLs, nonlinear time-history analysis and parametric study was done.

Nowadays, Steel PLATE SHEAR WALL (SPSW) is considered as a suitable alternative to conventional lateral load resisting systems that used for earthquake resistant design of structures, because of high post buckling strength, significant ductility, stable hysteresis characteristics and high initial stiffness. Also, steel PLATE SHEAR WALL has lighter weight of structures, increased floor area, quicker speed of construction, significant economically affordable and high quality control compared to a traditional reinforced concrete SHEAR WALLs. Study on behavior of steel PLATE SHEAR WALL began in 1970s with the aim of providing an easy method for the analysis and design. The initial experimental and analytical research clarified varies aspects of seismic behavior of steel PLATE SHEAR WALL, but it is still unknown, because of its complex behavior and design. Although some researches on steel PLATE SHEAR WALL has been done since the early 1980s, the appropriate performance of structures that had steel PLATE SHEAR WALL as lateral load resisting systems in the Northridge, USA (1994) and Kobe, Japan (1995) earthquakes caused researchers and working engineers to investigate and implement the steel PLATE SHEAR WALL system to a greater extent. Analytical and experimental research works and studies, provided primarily in Canadian, US and UK universities on steel PLATE SHEAR WALL considered different facets of the seismic behavior of steel PLATE SHEAR WALL and flourished the essential procedures for its application as an effective lateral load resisting system. However, in order to investigate the performance of steel PLATE SHEAR WALL comprehensively, wide range of nonlinear behavior has to be assessed and predicted and it requires hysteresis models that are capable to consider all deterioration modes. One of the comprehensive analytical hysteresis models is the modified Ibarra-Krawinkler (IK) deterioration model that provides four deterioration models including basic strength deterioration, post-cap strength deterioration, unloading stiffness deterioration and accelerated reloading stiffness deterioration for systems with bilinear, peak oriented and pinching behavior. In this study, by calibrating the modified Ibarra-Krawinkler deterioration model parameters for steel PLATE SHEAR WALLs with different properties, some equations are proposed to determine modified Ibarra-Krawinkler deterioration model parameters. First, one of the experimental specimens was modeled and analyzed in ABAQUS software and accuracy of results was measured. Then, 60 number of pinned joints-one story steel PLATE SHEAR WALLs with different infill PLATE thickness and bay length, using two types of steel for infill PLATE are numerically modeled and analyzed by ABAQUS software. Also, the height of steel PLATE SHEAR WALLs was kept constant equal to 3500 mm. Using OpenSees software numerical analysis results, the modified Ibarra-Krawinkler deterioration model parameters are calibrated. Then, by identifying the effective and pertinent factors, some statistical equations are suggested. According to the results, effective parameters on lateral load resisting capacity, elastic stiffness and post capping stiffness were thickness of infill PLATE and its steel type and ratio of bay length to height of steel PLATE SHEAR WALL. Also according to the results, ratio of bay length to height of steel PLATE SHEAR WALL had more influence on modified Ibarra-Krawinkler deterioration model parameters.

Flat-slab building structures exhibit significant higher flexibility compared with traditional frame structures, and SHEAR WALLs (SWs) are vital to limit deformation demands under earthquake excitations. The objective of this study is to identify an appropriate finite element (FE) model of SW dominant flat-PLATE reinforced concrete (R/C) buildings, which can be used to study its dynamic behavior. Three-dimensional models are generated and analyzed to check the adequacy of different empirical formulas to estimate structural period of vibration via analyzing the dynamic response of low- and medium-height R/C buildings with different cross-sectional plans and different SW positions and thicknesses. The numerical results clarify that modeling of R/C buildings using block (solid) elements for columns, SWs, and slab provides the most appropriate representation of R/C buildings since it gives accurate results of fundamental periods and consequently reliable seismic forces. Also, modeling of R/C buildings by FE programs using shell elements for both columns and SWs provides acceptable results of fundamental periods (the error does not exceed 10%). However, modeling of R/C buildings using frame elements for columns and/or SWs overestimates the fundamental periods of R/C buildings. Empirical formulas often overestimate or underestimate fundamental periods of R/C buildings. Some equations provide misleading values of fundamental period for both intact and cracked R/C buildings. However, others can be used to estimate approximately the fundamental periods of flat-PLATE R/C buildings. The effect of different SW positions is also discussed.