بررسی عددی و آزمایشگاهی اثر جداشدگی آرماتورهای طولی در محل اتصال تیر و ستون

نوع مقاله : مقاله کامل پژوهشی

نویسندگان

1 گروه مهندسی عمران، پردیس بین الملل دانشگاه ارومیه

2 دانشکده فنی مهندسی، دانشگاه ارومیه

10.22034/ceej.2024.61245.2350

چکیده

جداسازی میلگردهای طولی روشی شناخته شده برای کاهش کرنش پلاستیک میلگرد طولی در تیرهای بتنی است. از طرفی استفاده از غلاف دور میلگرد طولی بیشتر از دیدگاه کنترل رفتار کمانشی میلگرد مورد بررسی محققین مختلف بوده است. در این تحقیق اثر جداسازی با غلاف لاستیکی روی رفتار هیسترزیس تیرهای بتنی، کمانش میلگرد طولی و میزان موضعی­ شدن آسیب در محل مفصل پلاستیک مورد بررسی قرار می­ گیرد. میزان موضعی­ شدن آسیب از نظر قابلیت تعمیرپذیری و همچنین از نظر احتمال وقوع شکست برشی و برشی- لغزشی در محل مفصل پلاستیک بسیار مهم می ­باشد. دو نمونه آزمایشگاهی با و بدون غلاف تحت بارگذاری رفت و برگشتی آزمایش شدند. در ادامه با استفاده از مدل اجزای محدود LS-DYNA رفتار دو نمونه با استفاده از تحلیل عددی مورد بررسی قرار گرفت. نتایج نشانگر عدم تأثیر محسوس غلاف در رفتار هیسترزیس و کمانش میلگرد می ­باشد. همین نتایج نشان دادند که غلاف به شکل محسوسی از موضعی ­شدن آسیب، جلوگیری می ­نماید که قابلیت تعمیرپذیری نمونه را بهبود می ­بخشد. نتایج نشانگر آن است که با استفاده از غلاف و بدون تغییر محسوسی در روش ساخت فعلی تیرهای بتنی می­توان در تیرهای بتنی به­ طرز محسوسی نیاز به تعمیر را در زلزله ­های قوی کاهش داد. کاهش میزان موضعی ­شدن آسیب (ترک ­ها) در ضمن می­تواند احتمال وقوع شکست برشی و برشی- لغزشی را کاهش دهد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental and Numerical Study on the Effect of Logitudinal Reinforcment Debonding at Beam-Column Connections

نویسندگان [English]

  • Sahand Sadeghi Moghadamy 1
  • Saeed Tarverdilo 2
  • Mohammad Reza Sheidaii 2
1 Faculty of Civil Engineering, University of Urmia, Urmia 5756151818, Iran
2 Faculty of Civil Engineering, University of Urmia, Urmia 5756151818, Iran
چکیده [English]

     In concrete beams, plastic hinges form at the beam-column connections, playing a crucial role in providing the required ductility. Due to the high stress and strain in this area, failure typically initiates as flexural and flexural-shear cracks. High-rise concrete beams are prone to single cracks in the critical region, reducing the plastic hinge length. Additionally, the longitudinal strains applied to the reinforcement in this area are high, leading to the buckling of the longitudinal reinforcement. This study aims to improve the behavior of high-rise reinforced concrete beams under cyclic loading by introducing a rubber sheath to separate the reinforcement and concrete at the plastic hinge. Full-scale specimens were tested under cyclic loading and numerically analyzed. The primary goal is to enhance the behavior of high-rise reinforced concrete beams under cyclic loading by using a rubber sheath to separate the reinforcement and concrete. The rubber sheath separation not only improved shear behavior but also reduced crack width. The number of cracks and the extent of damage at the end of the test were significantly reduced in the concrete specimen with the rubber sheath. This reduction in damage increases structural safety and reduces repair costs after events such as earthquakes. In the final part of this study, a finite element model was developed, and modeling parameters in the reinforcement-concrete interaction models were examined to achieve a numerical model with results close to the experimental tests conducted in the laboratory.

کلیدواژه‌ها [English]

  • Bar buckling
  • Concrete beam
  • Plastic hinge
  • Debonding
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