نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد، مهندسی هوافضا، دانشگاه صنعتی شاهرود، شاهرود

2 استاد، مهندسی مکانیک، دانشگاه صنعتی مالک اشتر، تهران، ایران

3 - استادیار، مهندسی مکانیک، دانشگاه صنعتی شاهرود، شاهرود، ایران

4 دانشجو دکترا و مربی دانشگاه پدافند هوایی خاتم الانبیاء (ص)، مهندسی هوافضا، دانشگاه صنعتی مالک اشتر، تهران، ایران

چکیده

در این مقاله، مقادیر بهینه­ی پارامترهای مؤثر بر توزیع تنش اطراف گشودگی پنج ضلعی واقع در صفحه ارتوتروپیک تحلیل و بررسی می‌شوند. برای تعیین پارامترهای بهینه به‌منظور دست‌یابی به کمترین مقدار تنش در اطراف گشودگی از الگوریتم بهینه‌سازی رقابت استعماری استفاده شده است. الگوریتم رقابت استعماری روشی در حوزه محاسبات تکاملی است که به یافتن پاسخ بهینه مسائل می‌پردازد. این الگوریتم با تقلید از روند تکامل اجتماعی، اقتصادی و سیاسی کشورها و با مدل­سازی ریاضی بخش­هایی از این فرآیند، عملگرهایی را در قالب منظم به‌صورت الگوریتم ارائه می‌دهد که می‌توانند به حل مسائل پیچیده بهینه‌سازی کمک کنند. پایه‌های اصلی این الگوریتم را سیاست هم‌سان‌سازی، رقابت استعماری و انقلاب تشکیل می‌دهند. در واقع این الگوریتم جواب­های مسئله‌ی بهینه‌سازی را در قالب کشورها نگریسته و سعی می‌کند در طی فرآیندی تکرار شونده این جواب‌ها را رفته رفته بهبود داده و در نهایت به جواب بهینه مسئله برساند. روش استفاده شده در این مقاله، بسط روش تحلیلی است که برای گشودگی دایروی و بیضوی توسط لخنیتسکی انجام شده است. متغیّرهای طراحی در این پژوهش شامل زاویه الیاف، زاویه­ی بار، شعاع انحنای گوشه گشودگی، زاویه چرخش گشودگی و در نهایت جنس صفحه می‌باشد. نتایج حاصل شده از الگوریتم بهینه‌سازی رقابت استعماری بیانگر مناسب بودن این روش در بهینه‌سازی صفحات ارتوتروپیک می‌باشد. برای اثبات درستی نتایج، از حل عددی اجزای محدود استفاده شده است. نتایج نشان می‌دهند با انتخاب مناسب پارامترهای بهینه می‌توان مقدار تنش اطراف گشودگی را به‌میزان قابل توجهی کاهش داد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Determination of Optimal Parameters for Orthotropic Plates with Pentagonal Cutout by Imperialist Competitive Algorithm

نویسندگان [English]

  • Mohammad Hossein Mohammad Hossein Bayati Chaleshtari1 1
  • Keramat Malekzadeh Fard 2
  • Mohammad Jafari1 3
  • Ali Reza Pourmoayed 4

1 Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran

2 Department of Mechanical Engineering, MalekAshtar University, Tehran, Iran

3 Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran

4 Department of Mechanical Engineering, Malek Ashtar University and Inst Khatamul-Anbiya Air Defense University, Tehran, Iran

چکیده [English]

One of the designers concerns is structural failure as a result of stress concentration in the geometrical discontinuities. Understanding the effective parameters on stress concentration and proper selection of these parameters enables the designer to achieve a reliable design. In the analysis of perforated orthotropic plate, the effective parameters on stress distribution around cutouts include fiber angle, load angle, curvature radius of the corner of the cutout, rotation angle of the cutout and at last material of the plate. This paper tries to examine effective parameters on stress analysis of infinite orthotropic plate with central pentagonal cutout with imperialist competitive algorithm (ICA) introduced the optimum parameters to achieve the least amount of stress around the cutout. Like other evolutionary algorithms, ICA is becoming an important tool for optimization and other complex problem solving. The results reported in this review provide evidence of performance achievement of the ICA in terms of both computing time and quality of solution. In this paper, an analytical method has been used to Lekhnitskii theory for circular and elliptical cutouts. Finite element numerical solution is employed to examine the results of present analytical solution. Overlap of the results of the two methods confirms the validity of the presented solution. Results show that by selecting the aforementioned parameters properly, less amounts of stress could be achieved around the cutout leading to an increase in load-bearing capacity of the structure.

کلیدواژه‌ها [English]

  • Perforated Plates
  • Pentagonal Cutout
  • Imperialist Competitive Algorithm
  • analytical solution
 
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