ارزیابی ضریب کاهش شکل پذیری مهاربندهای ضربدری واقع در دو دهانه ابتدا و انتهای قاب های ساختمانی ساده

نوع مقاله : مقاله پژوهشی

نویسنده

دانشکده مهندسی عمران، دانشگاه صنعتی ارومیه، ارومیه، ایران

چکیده

در این تحقیق تلاش شده است ضریب کاهش شکل‌پذیری قاب‌های مهاربندی شده ضربدری معمولی و ویژه که در دو دهانه کناری قرار دارند، مورد ارزیابی قرار گیرد. بر اساس نتایج بدست آمده از این تحقیق، از نظر میزان مصالح مصرفی قاب‌های مهاربندی شده ضربدری ویژه و واقع در دو دهانه کناری نسبت به قاب‌های مهاربندی شده معمولی بترتیب برای قاب‌های یک تا شانزده طبقه از 15 الی 45 درصد مقرون به صرفه‌تر است. در شانزده قاب یک تا شانزده طبقه مهاربندی شده ضربدری معمولی به جز در قاب شانزده طبقه در بقیه قاب‌ها، ضریب کاهش شکل‌پذیری از مقدار مورد نظر آئین‌نامهASCE7 بیشتر بوده و در اینگونه قاب‌های مهاربندی شده ضربدری و واقع در دو دهانه کناری مشکلی از حیث تامین شکل‌پذیری مورد نیاز مشاهده نگردید. همچنین بر اساس نتایچ حاصله، با وجود اینکه ضریب رفتار پیشنهاد شده در پیش‌نویس استاندارد 2800 ایران برای قاب‌های مهاربندی شده همگرای ویژه منطقی‌تر از ضریب رفتار پیش‌بینی شده در آئین‌نامه ASCE7 است، لیکن مطابق نتایج بدست آمده از این تحقیق برای شانزده قاب مهاربندی شده ضربدری ویژه و واقع در دو دهانه کناری، ضریب رفتار باید کمتر از 5/5 در نظر گرفته شود.

کلیدواژه‌ها


عنوان مقاله [English]

Evaluation of Ductility Reduction Factor for X-braced Steel Frames Which are Braced in Two End spans

نویسنده [English]

  • A. Asghari
Faculty of Civil Engineering, Urmia University of Technology, Urmia, Iran
چکیده [English]

In this study, the ductility reduction factor of Ordinary Concentrically Braced Frames
(OCBFs) and special concentrically braced frames (SCBFs) which are braced concentrically in two end
sides of frames, is evaluated. The results confirmed that, using SCBFs will reduce about 15 to 45 percent
of total used material for one to 16 story frames respectively. In addition, for all of the 16 ordinary
X-braced frames, which have 1 to 16 story height, calculated ductility reduction factor exceeds from
ASCE7’s proposed one, except for 16 stories frame. For studied frames, which are braced in two end
sides, using the X-bracing system, the results confirmed that ductility demand is achievable without any
significant problem. In addition, results indicated that although the response modification factor which is
proposed by Iranian seismic design code (2800 standard), is more logical than ASCE7’s one, for frames
which are braced in the end sides, the response modification factor should be taken less than 5.5.

کلیدواژه‌ها [English]

  • Ductility
  • Ductility reduction factor
  • Concentrically braced frame
  • pushover analysis
  • Target displacement
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