مطالعه تأثیر پارامترهای هندسه تیر پیوند برشی پیچی قابل تعویض با اتصال به جان در برابر بارگذاری چرخه ای

نوع مقاله : علمی - پژوهشی

نویسندگان

1 استادیار ، موسسه آموزش عالی جهاد دانشگاهی خوزستان، ایران

2 دانش آموخته کارشناسی ارشد سازه، موسسه آموزش عالی فخر رازی ساوه

چکیده

مهاربند برون‌محور (EBF) به دلیل شکل‌پذیری و سختی، موردتوجه آیین‌نامه‌های طراحی لرزه‌ای است. اخیراً به‌کارگیری تیر پیوند قابل تعویض RLB به‌عنوان روشی نوین در رفع اشکالات طراحی سیستم EBF پیشنهاد شده است. در این روش با جدا کردن المان تسلیم شونده (تیر پیوند) از تیر اصلی کف، ترمیم و تعویض تیر پیوند بعد از آسیب به‌آسانی امکان‌پذیر است. یکی از انواع رایج RLB، تیر پیوند با مقطع دوبل ناودانی با اتصال پیچی به جان است. مطالعه عوامل تأثیرگذار بر رفتار این نوع تیر پیوند کمتر در مطالعات دیده شده است. پس در این مقاله به کمک نرم‌افزار آباکوس ابتدا اعتبارسنجی مدل‌سازی عددی نسبت به یک مدل آزمایشگاهی انجام شد. سپس با تغییر در اجزا اتصال اعتبارسنجی شده (اعم از تعداد و ضخامت ورق‌ها، تعداد و فاصله پیچ‌ها، تعداد و نوع فولاد مقطع تیر پیوند) درمجموع 16 مدل عددی جدید تولید و در برابر بارگذاری چرخه‌ای ارزیابی گردید. نتایج در محدوده فرضیات این مقاله نشان می‌دهد در پیوند برشی افقی تعویض‌پذیر با اتصال جان، تسلیم برشی کامل روی داده و نقش کامل «فیوز» لرزه‌ای شکل‌پذیر حاصل شد. بعلاوه RLB با اتصال پیچی جان عملکرد لرزه‌ای و ظرفیت دوران پلاستیک مطلوبی را داراست. همچنین با انتخاب هوشمندانه اجزا تشکیل‌دهنده تیر پیوند، ظرفیت مقاومت برشی، سختی، شکل‌پذیری و استهلاک انرژی افزایش می‌یابد. دراین‌بین تأثیر افزایش شماره مقطع تیر محسوس‌تر است. ضمناً برای تضمین رفتار تسلیم شوندگی برشی کامل RLB، تعبیه ورق تقویتی بال فوقانی و تحتانی در مجاورت اتصال الزامی است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Analytical Study of Geometric Effects of Bolted Web Replaceable Shear Link with Bolted Web Connection under Cyclic Loading

نویسندگان [English]

  • Navid Siahpolo 1
  • Nasreh Soveini 2
1 Assistant Professor, Deptartment of Civil Engineering, Institute for High Education ACECR, Ahvaz, Iran
2 Department of Civil Engineering, Fakhr-e-Razi Institute for Higher Education
چکیده [English]

Due to good ductility and stiffness, the eccentrically braced frame (EBF) has attracted the interest of seismic design regulations. Recently, the replaceable link beams (RLBs) were proposed as a new approach to solve the problems in designing the EBF system. This approach allows to easily repair or replace the damaged link beam by uncoupling the yielding element (link beam) from the main floor beam. One of the most common types of RLB is the double-channel link beam with the web-bolted connection. The identification of factors involved in the behavior of this type of link beam is less commonly found in the studies. In this paper, therefore, using the ABAQUS software, the numerical modeling was first validated to a laboratory model. Then, by changing the validated link components (including the number and thickness of plates, number and spacing of bolts, number and steel grade of link beam section), a total of 16 new numerical models were generated and evaluated under cyclic loading. The results limited to the assumptions of this paper show that in the web-connected horizontal replaceable shear link, the full shear yielding occurred, achieving the full functionality of ductile seismic fuse. In addition, the bolted, web-connected RLB demonstrates excellent seismic performance and plastic rotation capacity. Also, the smart selection of link components increases the shear strength capacity, stiffness, ductility and energy dissipation. However, the effect of increasing the size of beam cross-section is more noticeable. In addition, in order to ensure the full shear yielding behavior for RLB, it is necessary to add the upper and lower flange stiffeners near the connection.

کلیدواژه‌ها [English]

  • Bolted replaceable link-beam
  • Shear Yielding
  • Finite element model
  • cyclic loading
  • rotation angle of link beam
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