بررسی عددی رفتار غیرخطی تیرهای عمیق بتنی دارای بازشوی مستطیلی در جان تقویت شده با نوار‌ FRP

نوع مقاله : مقاله پژوهشی

نویسنده

گروه عمران، دانشگده مهندسی، دانشگاه خوارزمی، تهران، ایران

10.22124/jcr.2023.22337.1580

چکیده

عمق زیاد تیرهای عمیق امکان ایجاد بازشو در جان را فراهم می‌کند. بازشو در تیرهای عمیق برای عبور لوله‌ها و فضاهای تاسیساتی در نظر گرفته می‌شود. وجود بازشوها در جان باعث قطع اعضای بند و بست خرپای معادل و کاهش ظرفیت بارپذیری و سختی تیر می‌شود که می‌تواند حتی باعث گسیختگی گردد. یک راه حل برای این مشکل استفاده از نوارهای تقویتی FRP است. در این تحقیق تأثیر ورق‌های تقویتی FRP بر ظرفیت باربری تیرهای عمیق بتنی دارای بازشوی مستطیل شکل بررسی شده است. برای این منظور ابتدا نمونه‌های آزمایشگاهی مرجع به روش اجزای محدود تحلیل عددی و صحت سنجی شدند. سپس برخی از پارامترهایی که ممکن بود روی پاسخ تیر عمیق تأثیرگذار باشند مانند تعداد، ابعاد و فواصل بازشوها، انتخاب و با ثابت نگاه داشتن سایر پارامتر‌ها، پاسخ تیر عمیق نسبت به تغییرات آن‌ها مورد بررسی قرار گرفت. نتایج نشان دادند که نمونه با ورق تقویتی BOX شکل ظرفیت باربری کمتری نسبت به ورق تقویتی U شکل داشته است. همچنین نمونه‌هایی با ورق FRP به شکل U نسبت به نمونه بدون ورق 38 درصد و نسبت به ورق BOX شکل 13 درصد ظرفیت باربری بیشتری دارند. با مقایسه نمونه های تقویت شده از نظر شکل‌پذیری و ضریب رفتار مشخص شد که ورق تقویتی U شکل عملکرد بهتری دارد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Numerical study of nonlinear behavior of deep concrete beams with rectangular opening in the web reinforced with FRP strip

نویسنده [English]

  • seyed shahab Emamzadeh
Civil Engineering, Kharazmi University, Iran,Tehran
چکیده [English]

The great depth of the deep beams allows the opening in the web. Openings in deep beams are intended for the passage of pipes and installation ducts. The presence of openings in the web cuts the members of the tie and strut in the equivalent truss and reduces the load-bearing capacity and ductility of the beam, which can even cause rupture. One solution to this problem is to use FRP reinforcing strips. In this research, the effect of FRP reinforcement sheets on the bearing capacity of deep concrete beams with rectangular opening has been investigated. For this purpose, reference laboratory samples were modeled and validated by finite element method with Abaqus software, then a number of parameters that may affect the response of the deep beam, such as the number, dimensions and distances of openings, were selected and kept constant. Other parameters, the response of the beam to its changes were examined. The results showed that the samples with BOX shaped reinforcement sheet had less bearing capacity than U-shaped reinforcing sheet. Also, samples with U-shaped FRP sheet have 38% more load capacity than sample without sheet and 13% more than BOX sheet. By comparing the reinforced specimens in terms of ductility and coefficient of behavior, it was found that the U-shaped reinforcing sheet has better performance.

کلیدواژه‌ها [English]

  • Deep beam
  • Behavior factor
  • Ductility
  • Web opening
  • FRP strip

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