ارتعاشات آزاد ورق‌های نانوکامپوزیتی متخلخل مدرج تابعی تقویت شده با نانوتراشه‌های گرافنی با اشکال هندسی مختلف روی بستر الاستیک با روش تحلیلی پی‌ریتز

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی مکانیک، دانشگاه گیلان، رشت، ایران

2 گروه مهندسی مکانیک، واحد لاهیجان، دانشگاه آزاد اسلامی، لاهیجان، ایران.

چکیده

در این مطالعه، ارتعاشات آزاد ورق‌های نانوکامپوزیتی متخلخل مدرج تابعی تقویت شده با نانوتراشه‌های گرافنی در اشکال هندسی مستطیلی، مثلثی و بیضوی بر روی بستر الاستیک در شرایط مرزی مختلف مورد تحلیل و بررسی قرار می‌گیرد. از تئوری ورق مرتبه اول برشی برای مدلسازی ورق و از مدل پاسترناک برای مدلسازی بستر الاستیک استفاده می‌شود. سه نوع توزیع نانو‌تراشه گرافنی و سه نوع توزیع تخلخل در راستای ضخامت برای ورق نانوکامپوزیتی در نظر گرفته می‌شود. خواص مؤثر مادی نانوکامپوزیت با استفاده از یک مدل میکرومکانیکی بدست می‌آید. با نوشتن فانکشنال انرژی سیستم و بکارگیری روش تحلیلی پی‌ریتز، نتایج عددی برای بررسی اثرات ضریب تخلخل، درصد وزنی نانوتراشه‌های گرافنی، پارامترهای بستر الاستیک و همچنین نسبت طول به عرض و ضخامت ورق بر فرکانس طبیعی ارائه می‌شود. نشان داده می‌شود که ورق با الگوی توزیع تخلخل غیریکنواخت و متقارن نوع اول و چیدمان نوع اول نانوتراشه‌های گرافنی دارای بیشترین فرکانس طبیعی است. همچنین، با افزایش ضریب تخلخل، فرکانس طبیعی ورق برای تمامی الگو‌های توزیع نانوتراشه‌های گرافنی کاهش می‌یابد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Free Vibrations of Embedded Functionally Graded Graphene Platelets Reinforced Porous Nanocomposite Plates with Various Shapes Using P-Ritz Method

نویسندگان [English]

  • Mohammad Ziyafat Doust Abed 1
  • Raheb Gholami 2
  • Reza Ansari 1
1 Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
2 Department of Mechanical Engineering, Lahijan Branch, Islamic Azad University, P.O. Box 1616, Lahijan, Iran
چکیده [English]

In this study, the free vibrations of functionally graded graphene platelet-reinforced porous nanocomposite plates with various shapes such as rectangular, elliptical, and triangular ones embedded on an elastic foundation are analyzed. To mathematically model the considered plate and elastic foundation, the first-order shear deformation plate theory, and Pasternak model are used, respectively. Three types of graphene nanoplatelet distribution patterns and porous dispersion types through the thickness are considered for the nanocomposite plate. To obtain the effective material properties of the considered nanocomposite, a micromechanical model is employed. Then, the energy functional of considered functionally graded graphene platelet-reinforced porous nanocomposite plates are expressed, and the analytical P-Ritz method is used to solve the vibration problem corresponding to different shapes and boundary conditions, the influences of porosity coefficient, the weight fraction of graphene nanoplatelets, elastic foundation coefficients and also the lengths-to-width and -thickness ratios on the natural frequency are analyzed. It is illustrated that the plate with non-uniform and symmetric of first type porosity distribution pattern and the first type graphene nanoplatelets has a higher natural frequency. Also, by increasing the porosity coefficient, the natural frequency of the plate associated with all patterns of graphene nanoplatelets is reduced.

کلیدواژه‌ها [English]

  • Free vibration
  • Porous nanocomposite plates
  • Plates with various shapes
  • Elastic foundation
  • P-Ritz method
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