نویسندگان

دانشکده مکانیک، دانشگاه صنعتی شاهرود، شاهرود

چکیده

در این مقاله، طراحی بهینه ورق همسانگرد محدود حاوی گشودگی شش‌ ضلعی تحت بارگذاری درون صفحه‌ای با استفاده از الگوریتم‌های فرا ابتکاری مورد بررسی قرار گرفته است. الگوریتم تکامل تفاضلی و الگوریتم جستجوی هارمونی از دسته الگوریتم‌های تکاملی، الگوریتم بیگ بنگ- بیگ کرانچ از دسته الگوریتم‌های مبتنی بر فیزیک و الگوریتم گرگ خاکستری و الگوریتم اجتماع ذرات از دسته الگوریتم‌های هوش ازدحامی، پنج الگوریتم بهینه‌سازی مورد استفاده در این مقاله هستند. نتایج به‌دست آمده از مقایسه این الگوریتم‌ها، دلالت بر عملکرد بالا در فضای جستجو، سرعت مناسب در همگرایی و رقابتی بودن الگوریتم گرگ خاکستری جهت اجنتاب از نقطه بهینه محلی نسبت به چهار الگوریتم دیگر دارد. در تحلیل ورق همسانگرد محدود حاوی گشودگی شش‌ ضلعی پارامترهایی از جمله انحنای گوشه‌های گشودگی، زاویه چرخش گشودگی، نسبت اضلاع ورق، نسبت اندازه گشودگی به طول مشخصه ورق و نوع بارگذاری به‌عنوان پارامترهای مؤثر بر توزیع تنش محسوب می‌شود. در مطالعه حاضر، روش به‌کار گرفته ‌شده برپایه حل تحلیلی متغیر مختلط موشخیلشویلی است و از نگاشت همنوا برای ساده‌سازی روند حل معادلات استفاده شده است. ورق محدود (نسبت قطر دایره محیط به بزرگ‌ترین ضلع ورق، بزرگ‌تر از 2/0)، همسانگرد و الاستیک خطی درنظر گرفته ‌شده است. از روش اجزای محدود، برای بررسی درستی جواب‌ها استفاده شد. نتایج عددی، تطابق خوبی با نتایج حاصل از حل تحلیلی حاضر دارد. نتایج نشان می‌دهند با انتخاب مناسب پارامترهای بهینه می‌توان مقدار تنش اطراف گشودگی شش‌ ضلعی را به میزان قابل توجهی کاهش داد.

کلیدواژه‌ها

عنوان مقاله [English]

Optimized Design of Finite Isotropic Plates with Hexagonal Cutout by Metaheuristic Algorithms

نویسندگان [English]

  • m. h. bayati chaleshtari
  • m. jafari

چکیده [English]

This paper aims at optimizing the finite isotropic plates with the hexagonal cutout subjected to  plane loading using metaheuristic optimization algorithms. This research uses Differential Evolution Algorithm (DE) and Harmony Search Algorithm (HSA) from the evolutionary algorithm category, Big Bang- Big Crunch Algorithm (BB-BC) from the physics-based algorithm category, and Grey Wolf Optimizer Algorithm (GWO) and Particle Swarm Optimization (PSO) from the SI algorithm category; then the results of these algorithms are compared with each other. The results indicate that the grey wolf optimizer has the complete performance, short solution time and the ability to avoid local optimums. In the analysis of finite isotropic plate, the effective parameters on stress distribution around the  hexagonal cutouts are cutout bluntness, cutout orientation, plate’s aspect ratio, cutout size, and type of loading. In this study, with the assumption of plane stress conditions, the analytical solution of Muskhelishvili’s complex variable method and conformal mapping is utilized. The plate is considered to be finite (the proportion ratio of the  diameter of circle circumscribing to the longest plate side should be more than 0.2), isotropic, and linearly elastic. The finite element method has been used to check the accuracy of the  results. Numerical results are in a  good agreement with those of the present analytical solution. The results show that by selecting the aforementioned parameters properly, less amounts of stress could achieve around the cutout can lead  to an increase in the load-bearing capacity of the structure.

کلیدواژه‌ها [English]

  • Analytical Solution
  • Finite Isotropic Plates
  • Hexagonal Cutout
  • Metaheuristic Algorithms
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