نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشیار، دانشکده مهندسی مکانیک، دانشگاه کاشان، کاشان ، ایران

2 دانشجوی دکترا، دانشکده مهندسی مکانیک، دانشگاه کاشان، کاشان، ایران

3 استادیار، دانشکده مهندسی مکانیک، دانشگاه اصفهان، اصفهان، ایران

چکیده

در این پژوهش، تاثیر اندازه و موقعیت تورق بر پارامترهای ارتعاشی تیر کامپوزیتی متعامد متقارن چندلایه به روش‌های تحلیلی، اجزای محدود و تجربی ارایه شده است. در روش تحلیلی، تیر متورق به چهار زیرتیر تقسیم شده و دو مدل مود آزاد و مقید برای مدل‌سازی تداخل دو زیرتیر در محل تورق در نظر گرفته شده است. همچنین اثرات وابستگی کشش-خمش به‌دلیل تقسیم تیر به زیرتیرهای نامتقارن لحاظ شده است. در روش اجزای محدود، تیر کامپوزیتی با اندازه و موقعیت‌های مختلف تورق در نرم‌افزار اجزای محدود آباکوس شبیه‌سازی و فرکانس‌های طبیعی و شکل‌مودها از تحلیل مودال به‌دست آمده است. دو مدل مود آزاد و مقید با درنظرگرفتن شرایط مرزی، قیود، غیرخطی‌ها، شرایط تماسی و المان‌های مناسب شبیه‌سازی شده است. نتایج عددی دو مدل مود آزاد و مقید از هر دو روش تئوری برای تیر کامپوزیتی متعامد متقارن دارای تورق با اندازه و موقعیت‌های مختلف ارایه و مقایسه می‌شود. همچنین به‌منظور بررسی تاثیرات موقعیت طولی تورق‌های نسبتا کوچک بر سه فرکانس اول، پس از ساخت نمونه‌های کامپوزیت، آزمون‌های تجربی آنالیز مودال انجام و برای شرایط مرزی مختلف، فرکانس‌های طبیعی استخراج می‌شود. نتایج حاصل نشان می‌دهد که فرکانس‌های تحلیلی، اجزای محدود و تجربی تطابق خوبی با یکدیگر دارند.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Theoretical and experimental investigations of delamination effects on modal characteristics of symmetric cross-ply composite beams

نویسندگان [English]

  • Keivan Torabi 1
  • Mostafa Shariati-Nia 2
  • Mohammad Heidari-Rarani2 3

1 - Department of Mechanical Engineering, University of Kashan, Kashan, Iran

2 - Department of Mechanical Engineering, University of Kashan, Kashan, Iran

3 - Department of Mechanical Engineering, University of Isfahan, Isfahan, Iran

چکیده [English]

In this study, the effects of delamination size and location on vibration characteristics of laminated composite beams are investigated via analytical, finite element and experimental methods. In the analytical method, the delaminated beam is divided into four interconnected beams and the interaction of two sub-beams at the location of delamination is simulated by both constrained and free mode models. The effect of bending-extension coupling is taken into account in the analytical formulation. In finite element method, modal analysis is performed on the delaminated composite beams with different delamination sizes and locations and various boundary conditions using commercial finite element software, ABAQUS. Both free and constrained mode models are simulated in the finite element model using suitable interactions, nonlinearities and friction conditions. Analytical and finite element results of both constrained and free mode models are compared for a symmetric cross-ply delaminated composite beam with various sizes and locations of delamination. Also, in order to investigate the effects of axial location of relatively small delamination on the first three natural frequencies, modal tests are done on glass/epoxy composites for various boundary conditions. Results show that analytical, finite element and experimental frequencies have good agreement with each other.

کلیدواژه‌ها [English]

  • Laminated Composite Beam
  • Delamination
  • Vibration Analysis
  • Finite Element Method (FEM)
  • modal analysis

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