Seismic Design and Behavior of Low Yield Point Steel Plate Shear Walls

Tadeh Zirakian,Jian Zhang 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.1

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

Elastic lateral-distortional buckling of I-beams and the Meck Plot

Zirakian, Tadeh,Nojoumi, Seyed Ali Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.3

Meck Plot is an adapted version of the well-known Southwell method to the case of lateral-torsional buckling, which indeed reflects the physical inter-dependence of lateral flexure (lateral displacement) and torsion (rotation) in the structure. In the recent reported studies, it has been shown experimentally and theoretically that lateral displacement of an I-beam undergoing elastic lateral-distortional mode of buckling is interestingly directly coupled with other various deformation characteristics such as web transverse strain, web longitudinal strain, vertical deflection, and angles of twist of top and bottom flanges, and consequently good results have been obtained as a result of application of the Meck's method on lateral displacement together with each of the aforementioned deformation variables. In this paper, it is demonstrated that even web transverse and longitudinal strains, vertical deflection, and angles of twist of top and bottom flanges of an I-beam undergoing elastic lateral-distortional buckling are two-by-two directly coupled and the application of the Meck Plot on each pair of these deformation variables may still yield reliable predictions for the critical buckling load.

Elastic lateral-distortional buckling of I-beams and the Meck Plot

Tadeh Zirakian,Seyed Ali Nojoumi 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.3

Meck Plot is an adapted version of the well-known Southwell method to the case of lateraltorsional buckling, which indeed reflects the physical inter-dependence of lateral flexure (lateral displacement) and torsion (rotation) in the structure. In the recent reported studies, it has been shown experimentally and theoretically that lateral displacement of an I-beam undergoing elastic lateraldistortional mode of buckling is interestingly directly coupled with other various deformation characteristics such as web transverse strain, web longitudinal strain, vertical deflection, and angles of twist of top and bottom flanges, and consequently good results have been obtained as a result of application of the Meck’s method on lateral displacement together with each of the aforementioned deformation variables. In this paper, it is demonstrated that even web transverse and longitudinal strains, vertical deflection, and angles of twist of top and bottom flanges of an I-beam undergoing elastic lateraldistortional buckling are two-by-two directly coupled and the application of the Meck Plot on each pair of these deformation variables may still yield reliable predictions for the critical buckling load.

Hysteretic performance of SPSWs with trapezoidally horizontal corrugated web-plates

Hamed Kalali,Tadeh Zirakian,Mohammad Hajsadeghi,Farshid J. Alaee 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.2

Previous research has shown that steel plate shear walls (SPSWs) are efficient lateral force-resisting systems against both wind and seismic loads. A properly designed SPSW can have high initial stiffness, strength, and energy absorption capacity as well as superior ductility. SPSWs have been commonly designed with unstiffened and stiffened infill plates based on economical and performance considerations. Recent introduction and application of corrugated plates with advantageous structural features has motivated the researchers to consider the employment of such elements in stiffened SPSWs with the aim of lowering the high construction cost of such high-performing systems. On this basis, this paper presents results from a numerical investigation of the hysteretic performance of SPSWs with trapezoidally corrugated infill plates. Finite element cyclic analyses are conducted on a series of flat- and corrugated-web SPSWs to examine the effects of web-plate thickness, corrugation angle, and number of corrugation half-waves on the hysteretic performance of such structural systems. Results of the parametric studies are indicative of effectiveness of increasing of the three aforementioned web-plate geometrical and corrugation parameters in improving the cyclic response and energy absorption capacity of SPSWs with trapezoidally corrugated infill plates. Increasing of the web-plate thickness and number of corrugation half-waves are found to be the most and the least effective in adjusting the hysteretic performance of such promising lateral force-resisting systems, respectively. Findings of this study also show that optimal selection of the web-plate thickness, corrugation angle, and number of corrugation half-waves along with proper design of the boundary frame members can result in high stiffness, strength, and cyclic performances of such corrugated-web SPSWs.

Study of buckling stability of cracked plates under uniaxial compression using singular FEM

Sina Saberi,Parham Memarzadeh,Tadeh Zirakian 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.69 No.4

Buckling is one of the major causes of failure in thin-walled plate members and the presence of cracks with different lengths and locations in such structures may adversely affect this phenomenon. This study focuses on the buckling stability assessment of centrally and non-centrally cracked plates with small-, intermediate-, and large-size cracks, and different aspect ratios as well as support conditions, subjected to uniaxial compression. To this end, numerical models of the cracked plates were created through singular finite element method using a computational code developed in MATLAB. Eigen-buckling analyses were also performed to study the stability behavior of the plates. The numerical results and findings of this research demonstrate the effectiveness of the crack length and location on the buckling capacity of thin plates; however, the degree of efficacy of these parameters in plates with various aspect ratios and support conditions is found to be significantly different. Overall, careful consideration of the aspect ratio, support conditions, and crack parameters in buckling analysis of plates is crucial for efficient stability design and successful application of such thin-walled members.

Effect of crack location on buckling analysis and SIF of cracked plates under tension

Parham Memarzadeh,Sayedmohammad Mousavian,Mohammad Hosseini Ghehi,Tadeh Zirakian 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.35 No.2

Cracks and defects may occur anywhere in a plate under tension. Cracks can affect the buckling stability performance and even the failure mode of the plate. A search of the literature reveals that the reported research has mostly focused on the study of plates with central and small cracks. Considering the effectiveness of cracks on the buckling behavior of plates, this study intends to investigate the effects of some key parameters, i.e., crack size and location as well as the plate aspect ratio and support conditions, on the buckling behavior, stress intensity factor (SIF), and the failure mode (buckling or fracture) in cracked plates under tension. To this end, a sophisticated mathematical code was developed using MATLAB in the frame-work of extended finite element method (XFEM) in order to analyze the buckling stability and collapse of numerous plate models. The results and findings of this research endeavor show that, in addition to the plate aspect ratio and support conditions, careful consideration of the crack location and size can be quite effective in buckling behavior assessment and failure mode prediction as well as SIF evaluation of the cracked plates subjected to tensile loading.

Structural Performance of Steel Plate Shear Walls with Trapezoidal Corrugations and Centrally-Placed Square Perforations

Milad Bahrebar,Mohammad Zaman Kabir,Mohammad Hajsadeghi,Tadeh Zirakian,James B.P. Lim 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.3

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 webplate 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 forceresisting systems.

Numerical modeling of concrete cover cracking due to steel reinforcing bars corrosion

Mohammad Javad Mirzaee,Farshid Jandaghi Alaee,Mohammad Hajsadeghi,Tadeh Zirakian 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.61 No.6

Concrete cover cracking due to the corrosion of steel reinforcing bars is one of the main causes of deterioration in Reinforced Concrete (RC) structures. The oxidation level of the bars causes varying levels of expansion. The rebar expansions could lead to through-thickness cracking of the concrete cover, where depending on the cracking characteristics, the service life of the structures would be affected. In this paper, the effect of geometrical and material parameters, i.e., concrete cover thickness, reinforcing bar diameter, and concrete tensile strength, on the required pressure for concrete cover cracking due to corrosion has been investigated through detailed numerical simulations. ABAQUS finite element software is employed as a modeling platform where the concrete cracking is simulated by means of eXtended Finite Element Method (XFEM). The accuracy of the numerical simulations is verified by comparing the numerical results with experimental data obtained from the literature. Using a previously proposed empirical equation and the numerical model, the time from corrosion initiation to the cover cracking is predicted and then compared to the respective experimental data. Finally, a parametric study is undertaken to determine the optimum ratio of the rebar diameter to the reinforcing bars spacing in order to avoid concrete cover delamination.

Investigation of performance of steel plate shear walls with partial plate-column connection (SPSW-PC)

Mojtaba Gorji Azandariani,Majid Gholhaki,Mohammad Ali Kafi,Tadeh Zirakian,Afrasyab Khan,Hamid Abdolmaleki,Hamid Shojaeifar 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.39 No.1

This research endeavor intends to use the implicit finite element method to investigate the structural response of steel shear walls with partial plate-column connection. To this end, comprehensive verification studies are initially performed by comparing the numerical predictions with several reported experimental results in order to demonstrate the reliability and accuracy of the implicit analysis method. Comparison is made between the hysteresis curves, failure modes, and base shear capacities predicted numerically using ABAQUS software and obtained/observed experimentally. Following the validation of the finite element analysis approach, the effects of partial plate-column connection on the strength and stiffness performances of steel shear wall systems with different web-plate slenderness and aspect ratios under monotonic loading are investigated through a parametric study. While removal of the connection between the web-plate and columns can be beneficial by decreasing the overall system demand on the vertical boundary members, based on the results and findings of this study such detachment can lower the stiffness and strength capacities of steel shear walls by about 25%, on average.

Seismic response assessment of high-strength concrete frames strengthened with carbon fiber reinforced polymers

Javad Mokari Rahmdel,Farzin Vahid-Vahdattalab,Erfan Shafei,Tadeh Zirakian 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.77 No.6

In recent years, the use of new materials and technologies with the aim of developing high-performing and costeffective structures has greatly increased. Application of high-strength concrete (HSC) has been found effective in reducing the dimensions of frame members; nonetheless, such reduction in dimensions of structural elements in the most cases may result in the lack of accountability in the tolerable drift capacity. On this basis, strengthening of frame members using fiber reinforced polymers (FRPs) may be deemed as an appropriate remedy to address this issue, which albeit requires comprehensive and systematic investigations. In this paper, the performance of properly-designed, two-dimensional frames made of high-strength concrete and strengthened with Carbon Fiber Reinforced Polymers (CFRPs) is investigated through detailed numerical simulation. To this end, nonlinear dynamic time history analyses have been performed using the Seismosoft software through application of five scaled earthquake ground motion records. Unstrengthened (bare) and strengthened frames have been analyzed under seismic loading for performance assessment and comparison purposes. The results and findings of this study show that use of CFRP can be quite effective in seismic response improvement of high-strength-concrete structures.