Modares Civil Engineering journal
مهندسی عمران مدرس
MCEJ
Engineering & Technology
http://mcej.modares.ac.ir
1
admin
2476-6763
10.22034
fa
jalali
1391
8
1
gregorian
2012
11
1
12
4
online
1
fulltext
fa
برآورد ضریب مقاومت افزون سازههای مسلح به
دیوارهای برشی فولادی
Estimation of Overstrength Factor for Steel Plate
Shear Wall Structures
دیوارهای برشی فولادی از جمله سیستم های باربر جانبی با دو خصوصیت دلخواه سختی جانبی همراه شکل پذیری بسیار بالا است. با وجود داده های تحقیقاتی با ارزش درباره دیوارهای برشی فولادی، اطلاعات مربوط به طراحی لرزه ای این سیستم ها در بیشتر آئین نامه های لرزه ای (همچون استاندارد 2800 ایران) نیست و یا بسیار محدود است. از جمله پارامترهای عملکرد لرزه ای این سازه ها ضریب مقاومت افزون است. بیشتر مطالعات قبلی روی این ضریب، آزمایشگاهی بوده و محدود به قاب های کوتاه مرتبه و یا با مقیاس های کوچک آزمایشگاهی است. هدف این مقاله، ارائه فرمولی بسته برای تعیین ضریب مقاومت افزون دیوار های برشی فولادی برای قاب ها با ابعاد و ضخامت های ورق مختلف و با فرض اندرکنش قاب و ورق است. نتایج آزمایشگاهی دیگر محققین و همچنین تحلیل های اجزاء محدود در این پژوهش، مؤید درستی نتایج استفاده از فرمول بسته پیشنهادی است.
Steel plate shear walls are very effective lateral load resisting systems with high lateral stiffness and ductility capacity. Although there are valuable experimental data available for such systems, most of the current seismic codes (including Iran’s Std. 2800) provide none or limited design provisions for such structural systems. One of the important seismic performance parameters of the structures is “over-strength factor” which is implicitly or explicitly part of seismic design base shear formulation. Most of the available data on this factor are obtained from experimental research and therefore results are limited to low-rise structures and/or with reduced scaled structures. The main objective in this research is to assess the over-strength factor for the steel shear walls. A closed-form-solution is proposed for obtaining this factor based on plate-frame interaction. It was found that the over-strength factors obtained by this method are in line with available experimental data and analytical results obtained in this study.
In derivation of this closed form solution the following assumptions are made: 1) beam-to-column connection is rigid, 2) SPSW behaviour is affected by the interaction of the steel plate and its surrounding frame members, 3) the first storey, usually the soft storey, controls ductility and strength of the structure in general, 4) the beam remains rigid and the plastic hinges only form in the columns, 5) stresses due to the bending action in the plate do not interfere with the stresses due to buckling in the plate, 6) stress-strain relationship of the steel plate and the steel frame members are elastic-perfectly plastic.
The experiments on SPSWs used in this study were conducted in four major universities three of which in Canada and USA. The analytical model used in this study for finite element verification of the results is a three storey building that is adopted from a previous study on SPSW structures which was based on SAC buildings.
It was found that the overstrength factor of a multistorey SPSW structure can be estimated by that of only the first storey of that. Also the results for the overstrength factor are not that sensitive to the angle of tension field in the plate. Moreover, it was found that this factor decreases with a decrease of plate thickness and the yield stress of the plate.
دیوار برشی فولادی,ضریب مقاومت افزون,مدل اندرکنش قاب و ورق,آنالیز پوشآور
Steel plate shear walls,over-strength factor,plate-frame-interaction,pushover analysis
63
78
http://mcej.modares.ac.ir/browse.php?a_code=A-10-1000-9055&slc_lang=fa&sid=16
M.A.
Rahgozar
محمدعلی
رهگذر
100319475328460042182
100319475328460042182
Yes
University of Isfahan
دانشگاه اصفهان