بررسی شکل‌پذیری قاب‌های فولادی مهاربندی شدۀ ضربدری واقع در دو دهانۀ میانی مجاور هم

نوع مقاله : پژوهشی

نویسنده

• اباذر اصغری

دانشگاه صنعتی ارومیه

10.22067/civil.v27i2.33325

چکیده

در این تحقیق برای ارزیابی شکل‌پذیری قاب‌های ساختمانی ساده توأم با مهاربندهای ضربدری واقع در دو دهانۀ میانی مجاور هم، 16 قاب ساختمانی ساده توأم با مهاربندهای هم گرای معمولی و 16 قاب ساختمانی ساده توأم با مهاربندهای هم گرای ویژه مورد مطالعه قرار گرفته است. در قاب‌های مهاربندی شده ضربدری معمولی، با وجود آن که در اکثر قاب‌ها، سازه تغییرمکان هدف را تجربه نمی‌نماید، لیکن
به دلیل بالاتر بودن سطح نیروهای طراحی این نوع قاب‌ها، شکل‌پذیری مورد نیاز تأمین می‌شود. نتایج به دست آمده از این تحقیق نشان می‌دهد که ضریب رفتار پیشنهاد شده در ویرایش چهارم استاندارد 2800 ایران (5/5=R) برای مهاربندهای ضربدری ویژه منطقی‌تر از ضریب رفتار پیش‌بینی شده در آئین‌نامۀ ASCE7 (6=R) است. بر اساس نتایج این تحقیق، ضریب رفتار قاب‌های مهاربندی شدۀ ضربدری ویژه و دارای زمان تناوب محاسباتی بیش از یک ثانیه (حدوداً بالای 10 طبقه)، برابر 5 پیشنهاد می‌شود.

کلیدواژه‌ها

• ضریب رفتار

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عنوان مقاله [English]

Evaluating the Ductility of X-braced Frames which are Braced in two Middle Adjacent Spans

نویسنده [English]

• Abazar Asghari

Urmia University of Technology.

چکیده [English]

In this study, for evaluating ductility of ordinary concentrically braced frames (OCBFs) and special concentrically braced frames (SCBFs) which are X- braced in two adjacent middle spans, 16 steel ordinary concentrically braced frames and 16 special concentrically braced frames are studied. The results confirm that, although most of ordinary concentrically braced frames, which are X-braced, cannot experience the corresponding target displacement, but because of their high designing force level expected ductility can be obtained. Also results confirm that the response modification factor of SCBFs which is proposed by Iranian seismic design code (2800 standard forth edition), R=5.5, is more logical than ASCE's one, R=6. According to the results, the response modification factor of 5 is proposed for special concentrically braced frames, which have an analytical period of more than one second (frames more than 10 stories).

کلیدواژه‌ها [English]

• Ductility Reduction Factor
• Concentrically Braced Frame
• Pushover Analysis
• Target Displacement

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