نویسندگان
دانشکده مهندسی عمران، دانشگاه صنعتی اصفهان، اصفهان
چکیده
در این مقاله، حل مسائل مهندسی با معادلات هارمونیک که دارای تکینگی ضعیف یا ناپیوستگی در گرادیان تابع حل هستند برای مواد همگن و ناهمگن بررسی می‌شود. از آنجا که سایر روشهای عددی استاندارد از جمله روش اجزای محدود از پایه‌های هموار برای تقریب پاسخ مسئله استفاده می‌کنند و این پایه‌ها قادر به تطبیق خود با شرایط مجاور محدوده تکین نیستند، توابع دیگری نیز باید به پایه‌های اصلی اضافه شوند تا کیفیت حل را بهبود ببخشند. برای این منظور از توابع پایه متعادل‌شده به‌عنوان پایه‌های جدید در کنار پایه‌های چندجمله‌ای معمول روش اجزای محدود برای ساخت مجموعه‌ای از توابع شکل جدید استفاده می‌شود. این توابع از ارضای صورت همگن انتگرال وزنی معادله دیفرانسیل به‌دست می‌آیند و مرتبه تکینگی مسئله را به‌صورت خودکار تشخیص می‌دهند. توابع مذکور در المان‌های مجاور نقطه تکین در نظر گرفته می‌شوند. در نتایج عددی نشان داده خواهد شد که ترکیب این پایه‌ها با پایه‌های معمول در روش اجزای محدود، همگام با حفظ خواص مهم این روش منجر به بهبود کیفیت پاسخ آن به‌ویژه در مجاورت نقطه دارای تکینگی ضعیف می‌شود.
کلیدواژه‌ها
عنوان مقاله [English]
Solution of Harmonic Problems with Weak Singularities Using Equilibrated Basis Functions in Finite Element Method
نویسندگان [English]
- O. Bateniparvar
- N. Noormohammadi
- A. M. Salehi
چکیده [English]
In this paper, Equilibrated Singular Basis Functions (EqSBFs) are implemented in the framework of the Finite Element Method (FEM), which can approximately satisfy the harmonic PDE in homogeneous and heterogeneous media. EqSBFs are able to automatically reproduce the terms consistent with the singularity order in the vicinity of the singular point. The newly made bases are used as the complimentary enriching part along with the polynomial bases of the FEM to construct a new set of shape functions in the elements adjacent to the singular point. It will be shown that the use of the combined bases leads to the quality improvement of the solution function as well as its derivatives, especially in the vicinity of the singularity.
کلیدواژه‌ها [English]
- singularity
- Harmonic
- Equilibrated basis functions
- finite element method
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