ارزیابی عددی ظرفیت باربری دال بتن‌آرمه دارای بتن با مقاومت بالا تحت اثر بارهای انفجار

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری گروه سازه، دانشکده مهندسی عمران، دانشگاه سمنان، سمنان، ایران

2 پژوهشگر قرارگاه سازندگی خاتم الانبیا (ص)، تهران، ایران

چکیده

بتن با مقاومت بالا که دارای شکل‌پذیری و چقرمگی بالایی است، به‌طور گسترده‌ای در ساخت سازه‌های مدرن استفاده می‌شود. مشخصه برجسته بتن با مقاومت بالا بدین گونه است که در تحمل بارهای شدید از قبیل بار‌های ضربه‌ای یا انفجار از پتانسیل بسیار بالایی برخوردار است. در این مقاله به مدل‌سازی سه بعدی و تحلیل عددی یک دال بتنی با مقاومت بالا در نرم‌افزار اجزاء محدود LS-DYNA پرداخته می‌شود. برای این منظور سناریوهای مختلف بارگذاری انفجاری در نظر گرفته شده و پاسخ جابه‌جایی قائم و کانتور کرنش‌های پلاستیک دال تحت هر یک از این سناریوها مورد مطالعه قرار می‌گیرد. در این مدل عددی، اثر نرخ کرنش نیز بر رفتار دینامیکی مواد لحاظ می‌گردد. ملاحظه گردید که دال تحت بار انفجار با شدت بیشتر و فاصله کمتر ابتدا بیشترین جابه‌جایی را تجربه و سپس با گذشت زمان جابه‌جایی آن ماندگار می‌شود؛ این در حالی است که دال در حالت بار انفجار کم و فاصله زیاد از سطح دال، نسبت به موقعیت اولیه خود با یک پریود تقریباً یکسان نوسان کرده و دارای جابه‌جایی‌های اندکی است.

کلیدواژه‌ها


عنوان مقاله [English]

Numerical Assessment of the Reinforced Ultra-High Performance Concrete Slab Subjected to Blast loading

نویسندگان [English]

  • M. Mokhtari 1
  • M. Ebrahimi 2
1 Faculty of Civil Engineering, Semnan University, Semnan, Iran
2 Khatam‑al Anbiya Construction Headquarters
چکیده [English]

The ultra-high performance concrete which has high ductility and toughness, is widely used in the construction of new structures. The key feature of ultra-high performance concrete is that it has a very high potential in bearing strong loads such as impact loads or explosions. In this paper a 3D model of an ultra-high performance concrete slab is modeled and subjected to blast loading in LS-DYNA finite element software. To this end, different scenarios of blast loading are selected and the responses including the vertical displacement and the plastic strain contour of the slab are determined under each scenario. In this numerical model, the effect of strain rate on the dynamic behavior of materials is also considered. It is observed that when the slab is subjected to a shorter distance and stronger blast load, it first experiences the largest displacement and after that the displacement decreases and remains constant. However, in the case of exposure to a weaker blast load at a longer distance from the surface of the slab, the slab fluctuates relative to the initial position with an almost constant fluctuation period and has little displacements.

کلیدواژه‌ها [English]

  • RC Slab
  • Ultra-High Performance Concrete
  • Numerical Analysis
  • Blast
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