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STUDY OF HIGHER MODE EFFECTS AND LATERAL LOAD PATTERNS IN PUSHOVER ANALYSIS OF STEEL FRAMES WITH STEEL SHEAR WALL Mohammad Ghanoonibagha1, Mohammad Reza Ashrafi Gol2, Mohammad Reza Ranjbar3 1 Department of Civil Engineering, East Tehran Branch, Islamic Azad University, Tehran, Iran, e-mail: ghanoonibagha@iust.ac.ir 2 School of Civil Engineering, Iran University of Science and Technology, Narmak, Tehran, Iran 3 Technical Faculty of Mapping, Zabol University, Zabol, Iran ABSTRACT When an earthquake occurs, the structure will enter into a nonlinear stage; therefore, new approaches based on nonlinear analysis are needed to flourish with the purpose of more realistic investigations on seismic behavior and destruction mechanism of structures. According to the modern philosophy, “Performance-based Earthquake Engineering” is formed in which simple nonlinear static analyses are mostly used in order to determine the structure’s behavior in nonlinear stage. This method assumes that the structure response is only controlled by the main mode and the shape of this mode will remain the same, while it enters the nonlinear stage. Both of these assumptions are approximations, especially in high buildings, which have a long period. It seems that constant load pattern used in these methods cannot consider all of the effects properly. In this paper, an attempt was made to study the accuracy of these methods in comparison to nonlinear dynamic analysis, by considering various load patterns existing in FEMA, also load patterns proportional to higher modes in nonlinear static method, and employing an approximative method of MPA modal analysis, study the accuracy of these methods in comparison to nonlinear dynamic analysis. For this purpose, three steel frames of 4, 8, and 12-stories with steel shear wall have been studied. Keywords: load patterns, steel shear wall, static nonlinear, dynamic nonlinear. www.astrj.com/pdf-61926-4050?filename=STUDY%20OF%20HIGHER%20MODE.pdf STUDY OF HIGHER MODE.pdf

Comparison of plasticity and stiffness of steel shear walls with composite steel plate shear wall Leila Shahryari; Mahdi Esfandiari 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 منبع دانلود JSEG481443558600.pdf

Study of Non-linear Dynamic Behavior of Structures with Steel Shear Wall under the Near Fault Earthquakes Original Article, C55 Soltani P. and Tabatabaei Mirhosseini R. Journal. Civil Eng. Urban. 3(6):372-379. 2013 ABSTRACT:This paper deals with study of the steel shear walls and dynamic analysis of such structures under the earthquakes near fault. The studied frames in this paper have a span in 4-meter width and 3-meter height and are included 3 spans. We studied the dynamic of frames after modeling the frames in ABAQUS and giving the earthquake acceleration records near Kobe, Lomaprieta, and Northridge. The results showed that the increase of number of storey increases maximum storey displacement of moment frames. The increase of thickness the shear wall also will decrease the displacement of maximum storey because of decreasing the non-linear effects of shear wall and the delay on submission. Therefore, Base shear in moment frames of 3, 6, and 12-storey, not only depends on maximum acceleration and acceleration records, but also depends on the form of acceleration records. By increasing the number of the storey, this efficacy will be decreased so that the maximum acceleration would be more effective on the storey shear increase or decrease. We can say, by increasing the number of storey of vibration mode, maximum acceleration of storey has the regular process in each 3 acceleration record. It seems that the acceleration of storey not only is based on the type of acceleration record but also is based on the other elements such as increasing the thickness of shear wall and number of the storey. Maximum response in the last storey would not that change by increasing the thickness of shear wall but in the response of other storey, has 6 storey especially storey 3, 4, and 5 in the frame. We can conclude that acceleration of the storey compared to acceleration of column has had the increasing process, by watching the response of acceleration record. The increase of shear wall also decreases the acceleration of storey. Keywords:Dynamic Analysis, Near Fault, Steel Shear Wall, ABAQUS Software, Base Shear منبع: [Hidden Content] دانلود: [Hidden Content].,55-372-379.pdf J. Civil Eng. Urban.,55-372-379.pdf

Hysteretic Characteristics of Unstiffened Plate Shear Panels T. M. Roberts & S. Sabouri Ghomi School of Engineering, University of Wales College of Cardiff, Newport Road, Cardiff CF2 1XH, UK (Received 6 April 1990: accepted 10 June 1990) ABSTRACT A series of quasi-static cyclic loading tests on unstiffened plate shear panels is described, All the panels tested exhibited adequate ductility and stable S shaped hysteresis loops, with the energy absorbed per cycle increasing with the maximum amplitude of shear displacement. A theoretical model for predicting the hysteretic characteristics is presented, which incorporates the influences of shear buckling of the web plate and plastic yielding of the web plate and surrounding frame. Theoretical predictions are compared and show satisfactory agreement with the experimental results. The simplicity of the theoretical model is such that it can be readily incorporated in nonlinear dynamic analyses of steel plate shear walls. 1-s2.0-026382319190061M-main.pdf

The Effect of Out-of-Plane Flexural Stiffness of Boundary Frame on Buckling Stress Patterns of Steel Plate Shear Wall P. MEMARZADEH*, M. AZHARI†, M.M. SAADATPOUR† *Department of Civil Engineering, Islamic Azad University, Najafabad Branch, Najafabad †Department of Civil Engineering, Isfahan University of Technology, Isfahan IRAN mojtaba@cc.iut.ac.ir Abstract: - When buckling occurs in the infill plate of Steel Plate Shear Wall (SPSW), a diagonal tension field is formed through the plate. It seems that the lateral displacements of plate due to buckling may have a role in formation of the tension field. Meanwhile revealing this role, this paper investigates the influence of out-of-plane flexural stiffness of boundary members (i.e. beams and columns) on the buckling coefficients and the tension field behaviour of SPSW associated with the symmetric and anti-symmetric buckling modes. The linear buckling equations in the sense of von- Karman have been solved in conjunction with various boundary conditions, by using the Ritz method. Key-Words: - Steel shear wall, Thin plate, Shear buckling, Symmetric, Anti-symmetric, Ritz method, Principal stresses [Hidden Content] 54cba9df0cf24601c0886fc9.pdf