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Evaluation of Design Parameters on PBD of RC Buildings with Masonry Infills. Bhushan M. Raisinghani ABSTRACT Masonry infills are provided in almost all residential buildings as enclosure. The building analysis and designs are carried out considering a representative empirical time period. The yield strength of URM infilled frames is much higher, and yield displacement is smaller for bare frames, providing higher ductility. The extent of damage to infill elements define the hazard level imposed and the corresponding risk associated with it. In this paper, the performance of RC building with infills is evaluated using pushover analysis for various seismic hazard levels and loading patterns as per ATC40 & FEMA356 in ETABS. A seven storey regular RC building is located in seismic zone-V (IS1893-0.36 g). The parameters of evaluation include time period formula, modelling technique of infill, masonry units used in practice, and location of openings in building. The code provisions for open ground storey buildings have been evaluated for performance assessment. Under 0.36 g hazard level, the building frame satisfied Life Safety performance objective under the three lateral loading patterns. It is found that AAC masonry blocks least affect the performance of frame elements and also the required failure mode for the structure. منبع @Civilbest_ارزیابی_لرزه_ای_ساختمان.pdf

بهبود شکل پذیری و رفتار چرخه ای مهاربند شکافدار با استفاده از نبشی فولادی مجله علمی، پژوهشی: نشریه علمی و پژوهشی سازه و فولاد-شماره‌ي هفدهم بهار و تابستان 1394 نویسنده: سیدمهدی زهرایی، عبداله چراغی دانلود art-674371220.pdf

COMPARISON OF THE PROGRESSIVE COLLAPSE RESISTANCE OF SEISMICALLY DESIGNED STEEL SHEAR WALL FRAMES AND SPECIAL STEEL MOMENT FRAMES M. R. Sheidaii and S. Jalili Abstract In this study, the progressive collapse potential of seismically designed steel plate shear wall (SPSW) systems is investigated using the alternate path method, and their performances are compared with those of the conventional special moment frame (SMF) systems. Nonlinear static and dynamic analyses are conducted to follow the progressive collapse of the structures, and their ability of absorbing the destructive effects of member loss is investigated. The obtained results show that when a corner or a middle column in the first story of the SPSWs is removed, the rest of the structure is not able to provide an appropriate alternative path for redistributing the generated loads caused by member loss, and therefore the structure presents a high potential for progressive collapse. However, by changing the lateral load resisting system of these buildings with the SMFs, the progressive collapse resisting capacity of the buildings increases significantly. Keywords Progressive Collapse, Alternate Path Method, Nonlinear Static Analysis, Nonlinear Dynamic Analysis, Steel Plate Shear Wall چکیده در این مطالعه پتانسیل خرابی پیشرونده در قاب­های فولادی مقاوم لرزه­ای مجهز به دیوار برشی فولادی (SPSW) با استفاده از روش مسیر جایگزین بررسی شده و عملکرد آن­ها در برابر خرابی پیشرونده با سیستم­های قاب خمشی ویژه رایج (SMF)مقایسه شده است. تحلیل­های غیرخطی استاتیکی و دینامیکی برای تعقیب وقوع خرابی پیشرونده در سازه­ها انجام شده و قابلیت جذب اثرات مخرب حذف عضو، بررسی شده است. نتایج بدست آمده نشان می­دهد زمانی که یک ستون گوشه و یا یک ستون میانی واقع در طبقه اول از سیستم SPSW حذف می­شود، سازه باقیمانده نمی­تواند مسیر جایگزین مناسبی برای بازتوزیع بارهای ناشی از حذف عضو فراهم نماید و سازه پتانسیل بالایی را برای خرابی پیشرونده نشان می­دهد. ولی با تغییر سیستم باربر جانبی سازه از SPSW به SMF، ظرفیت باربری سازه در برابر خرابی پیشرونده بطور چشمگیری افزایش می­یابد. 28-6-7.pdf

Comparison of chevron and suspended-zipper braced steel frames Yigit Ozcelik a, Afsin Saritas b,⁎, Patricia M. Clayton a a Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX 78712, USA b Department of Civil Engineering, Middle East Technical University, Ankara 06800, Turkey a r t i c l e i n f o a b s t r a c t Article history: Received 22 June 2015 Received in revised form 14 November 2015 Accepted 8 December 2015 Available online xxxx a b s t r a c t Suspended-zipper braced frame is a modified configuration of chevron braced frame inwhich zipper columns are added between story beams and a hat truss is attached between top two stories in order to redistribute the unbalanced vertical forces emerging following the brace buckling to avoid the use of deep beams. In this study, three- and nine-story chevron and suspended-zipper braced frames are analyzed to compare their seismic performances. The beams, columns, braces and zipper columns are modeled using nonlinear force-formulation frame elements and nonlinear geometric effects are included by utilizing corotational transformation. Nonlinear static analyses are performed until reaching a roof drift ratio of 3% and a set of twenty ground motion records scaled to match a 10% probability of exceedance in 50 years is used for nonlinear time-history analysis. The results appear to indicate that the lateral load capacity and drift demands for both low-rise chevron and suspendedzipper braced frames are very similar; however, the mid-rise chevron braced frame has a better performance compared to the mid-rise suspended-zipper braced frame. © 2015 Elsevier Ltd. All rights reserved. Keywords: Steel structures Concentrically braced frames Chevron braced frames Suspended-zipper braced frames Nonlinear static analysis Nonlinear time-history analysis 10.1016_j.jcsr.2015.12.019-Comparison-of-chevron-and-suspended-zipper-braced-steel-frames.pdf

Seismic Performance of Steel Plate Shear Walls Using Nonlinear Static AnalysisDHAR, MOON MOON (2015) Seismic Performance of Steel Plate Shear Walls Using Nonlinear Static Analysis. Masters thesis, Concordia University. AbstractUnstiffened steel plate shear wall (SPSW) is considered as a primary lateral load resisting system due to its significant post-buckling strength, high ductility, stable hysteretic behaviors and robust initial stiffness. Nonlinear seismic analysis can accurately estimate structural responses, however, the method is very time consuming and may not be suitable for regular engineering practice. On the other hand, traditional pushover analysis method does not consider contributions of higher modes to the structural responses and thus, often do not provide good estimation of seismic responses for taller buildings. Capacity-Spectrum Method (CSM) and modal pushover analysis (MPA) are two simple nonlinear static methods that have been proposed and recently used for seismic performance evaluation of few lateral load-resisting systems. This research further examines the applicability of CSM and MPA methods to assess seismic performance of steel plate shear walls. A nonlinear finite element model was developed and validated with experimental studies. Three different SPSWs (4-, 8-, and 15-storey) designed according to capacity design approach were analysed by subjecting the steel shear walls under artificial and real ground motions for Vancouver. The CSM and MPA procedures were applied to analyse the selected SPSWs and the results were compared with more accurate nonlinear seismic analysis results. It is observed that both CSM and MPA procedures can reasonably predict the peak roof displacements for low-rise SPSW buildings. In addition, MPA procedure, which includes contributions of higher modes when estimating seismic demands of buildings, provides better predictions of critical seismic response parameters for taller SPSWs. منبع: [Hidden Content] دانلود: [Hidden Content]1/Dhar_MASc_S2015.pdf Dhar_MASc_S2015.pdf