نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجوی دکترا، دانشکده مهندسی مکانیک، دانشگاه تربیت مدرس، تهران، ایران

2 استاد، دانشکده مهندسی مکانیک، دانشگاه تربیت مدرس، تهران، ایران

چکیده

سازه‌های مخروطی کامپوزیتی به‌عنوان اجزای تشکیل دهنده سازه‌ای در صنایع هوافضا و دریایی و مهندسی عمران استفاده می‌شوند. در این تحقیق ارتعاشات آزاد مخروط کامپوزیتی مشبک با تکیه‌گاه ساده مطالعه شده است. تاکنون مطالعه روی آنالیز ارتعاشی این گونه از سازه‌ها انجام نشده است. از روش تحلیلی- تقریبی معادل‌سازی برای معادل کردن سفتی تقویت کننده‌ها استفاده شده که در آن تقویت کننده‌ها به‌صورت تیر در نظر گرفته شدند. این تقویت کننده‌ها قادر به تحمل نیروهای برشی و ممان خمشی نسبت به بارمحوری وارده می‌باشند. مسیر ژئودزیک برای تقویت کننده‌ها انتخاب و معادلات مربوط به آنالیز ارتعاشی بر مبنای تئوری دانل استخراج شده‌اند. از روش ریتز برای حل معادلات و استخراج فرکانس‌های طبیعی استفاده شد. یک مدل سه بعدی در نرم افزار آباکوس تهیه و نتایج حاصل از تحلیل با نتایج حاصل از نرم افزار آباکوس مقایسه شد. مقایسه‌ها توافق خوبی را نشان دادند. اثر تغییر پارامترهای هندسی و تغییر در زاویه بین تقویت کننده‌ها روی فرکانس ارتعاشات بررسی شد. نتایج حاضر جدید بوده و می‌تواند به عنوان مبنایی برای مطالعات آتی مورد استفاده قرار گیرد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Free vibration analysis of grid stiffened composite conical shells

نویسندگان [English]

  • Mehdi Zarei 1
  • Gholam Hossien Rahimi 2

1 Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran

2 Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran

چکیده [English]

Laminated composite conical shells are used as components of aerospace, marine industries and civil engineering structures. In this research free vibration of grid stiffened composite conical shell with simply support boundary condition is studied. No study has yet been done on vibration analysis of these structures. Smeared method is employed to superimpose the stiffness contribution of the stiffeners with those of shell in order to obtain the equivalent stiffness parameters of the whole structure. The stiffeners are considered as a beam and support shear loads and bending moments in addition to the axial loads. Geodesic path is applied to the stiffeners. Equations were derived using classical shell theory of Donnell type and were solved using energy functional with the Rayleigh-Ritz method. A 3D finite element model was built using ABAQUS software. Results were compared and validated for grid stiffened structure with ABAQUS software. Comparisons and validations revealed good agreements. The effects of shell geometrical parameters and variations in the cross stiffeners angle on the natural frequencies were investigated.Results given are novel and can be used as a benchmark for further studies.

کلیدواژه‌ها [English]

  • Free Vibrations
  • grid stiffened
  • smeared method
  • geodesic

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