نوع مقاله: مقاله پژوهشی

نویسنده

استادیار، آزمایشگاه مکانیک محاسباتی، مهندسی مکانیک، دانشگاه زنجان، زنجان، ایران

چکیده

هدف این مقاله مدل‌سازی پوسته ‌استوانه‌ای بسته کامپوزیتی و محاسبه میدان تنش، مخصوصا تنش‌های برون صفحه‌ای در پوسته‌های استوانه‌ای کامپوزیتی با طول محدود تحت بارگذاری شعاعی ‌می‌باشد. برای فرمول‌بندی مسئله از تئوری لایه‌ای بر مبنای جابه‌جایی بهره‌گیری شده است. با در نظر گرفتن فرم میدان جابه‌جایی مناسب برای پوسته استوانه‌ای کامل، فرمول‌بندی تئوری لایه‌ای برای مسئله استخراج شده است. ابتدا میدان کرنش پوسته در تئوری لایه‌ای به‌دست آمده و سپس با استفاده از اصل حداقل انرژی پتانسیل کل معادلات حرکت حاکم بر استوانه در تئوری لایه‌ای و شرایط مرزی متناسب برای آن استخراج شده است. معادلات حاکم بر مسئله به تعداد دلخواهی معادله دیفرانسیل کوپل بر حسب توابع جابه‌جایی تبدیل شده است. با تعریف متغیر مناسب، حل تحلیلی برای معادلات پوسته کامپوزیتی متعامد ارایه شده و شرایط مرزی در لبه‌های پوسته اعمال شده است. در قسمت نتایج عددی، پوسته کامپوزیتی متعامد از جنس کربن-اپوکسی با لایه‌گذاری متقارن و نامتقارن که تحت بارگذاری فشار داخلی یا خارجی است بررسی شده است. ابتدا همگرایی تنش‌ها نسبت به تعداد لایه‌های عددی در تئوری لایه‌ای مورد مطالعه قرار گرفته است و سپس توزیع میدان تنش و مخصوصا تنش‌های بین لایه‌ای در نزدیکی لبه‌های استوانه ارایه شده است و توزیع تنش‌های بین لایه‌ای عمودی و برشی در لایه مرزی نزدیک به لبه‌ها مطالعه شده است. ملاحظه شد که لایه‌گذاری تاثیر زیادی در اندازه و نحوه توزیع تنش‌های بین لایه‌ای دارد. همچنین مشاهده شد که اندازه بیشینه تنش بین لایه‌ای عمودی در لبه‌های آزاد پوسته از مقدار فشار داخلی اعمال شده به استوانه بزرگتر است و اندازه تنش بین لایه‌ای برشی در حدود اندازه فشار اعمالی می‌باشد.

کلیدواژه‌ها

عنوان مقاله [English]

Analysis of interlaminar stresses in cross-ply composite cylinders subjected to radial loads

نویسنده [English]

  • Isa Ahmadi

Center of Computational Mechanics, Department of Mechanical Engineering, University of Zanjan, Zanjan, Iran

چکیده [English]

In this study, the stress field and specially the interlaminar stresses in a composite cylinder with finite length which is subjected to radial load are studied. The displacement based layer-wise theory (LWT) of Reddy is used for formulation and solution of a composite cylinder which is subjected to internal and external pressure. The principle of minimum total potential energy is used to derive the governing equations and the appropriate boundary conditions (BC) for the problem. The governing equations of the problem include a set of coupled ordinary differential equations in the terms of the unknown displacement functions of the mathematical surfaces in the LWT. A set of new variables are defined and the governing equations of the problem are solved analytically. The free edge boundary conditions are considered in the analysis. In the numerical results, the distribution of the interlaminar stresses and in-plane stresses in the symmetric and un-symmetric laminated composite cylinders which are subjected to internal or external pressure are presented. It is seen that the layer stacking has important effect on the distribution and magnitude of the interlaminar stresses in the cylinder. It is observed that the maximum value of the interlaminar normal stresses in the free edge of the cylinder is bigger than the applied radial pressure and the interlaminar shear stress is in the order of the applied pressure.

کلیدواژه‌ها [English]

  • Interlaminar Stresses
  • Laminated Composite Cylinder
  • Layer-wise theory
  • Cross-ply layer stacking

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