مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

محاسبه ضرایب شدت تنش و تنش T برای ورق های ترک دار ترمیم شده با وصله های کامپوزیتی و فلزی یک طرفه و دو طرفه

نویسندگان
1 مجتمع دانشگاهی مکانیک و هوافضا، دانشگاه صنعتی مالک اشتر، شاهین شهر، اصفهان، ایران
2 شرکت صنایع هواپیماسازی ایران (هسا)، سازمان صنایع هوایی، شاهین شهر، ایران
چکیده
به دلیل ویژگی‌های ممتاز مواد مرکب مانند سبکی، استحکام بالا و قابلیت شکل پذیری خیلی خوب، استفاده از وصله‌های کامپوزیتی در ترمیم ورق‌های ترک خورده و دارای شکاف، روشی کارآمد را فراهم می‌کند. در این مقاله عملکرد وصله‌های متفاوت مشتمل بر وصله‌های کامپوزیتی و فلزی با محاسبه ضرایب شدت تنش و تنش T با استفاده از روش المان محدود سه بعدی مورد بررسی قرار گرفته است. ارزیابی نقش خمش خارج از صفحه در عملکرد ترمیم با وصله‌های یک طرفه از اهداف مهم دیگر انجام این مطالعه بود. نتایج نشان داده است که هرچه وصله کامپوزیتی مستحکم‌تر باشد، کاهش ضرایب شدت تنش بیش‌تر خواهد بود. در نمونه‌های مورد بررسی وصله بورن/اپوکسی عملکرد بسیار بهتری نسبت به وصله شیشه/اپوکسی دارد.‌ به علاوه، الحاق وصله‌های یک طرفه و دوطرفه، تغییر مقادیر تنش T را به همراه داشته که این تغییر برای زاویه ترک 0 درجه، بیش‌ترین و برای زاویه ترک 45 درجه کم‌ترین است. افزایش ضخامت چسب نیز منجر به افزایش ضریب شدت تنش در ورق ترمیم شده می‌شود. در نهایت مشخص شد، خمش خارج از صفحه نقش بسیار مهمی در عملکرد ترمیم با وصله‌های کامپوزیتی یک طرفه دارد.
کلیدواژه‌ها

عنوان مقاله English

Computation of stress intensity factors and T- stress for cracks repaired by single and double composite and metallic patches

نویسندگان English

Ehsan Barati 1
alireza salmanian mobarakeh 1
Ghasem Sadeghi 2
1 Mechanical and Aerospace Engineering Department, Malek-Ashtar University of Technology, Shahinshahr, Esfahan, Iran.
2 Iran Aircraft Manufacturing Industrial Company (HESA), Iran Aviation Industries Organization, Shahinshahr, Iran
چکیده English

Due to various benefits of composite materials such as light weight, high strength and their excellent formability, the externally bonded composite patches have been proved to be a preferable method of repairing flaws and cracks in various engineering structures. In this paper, the behavior of various patches such as composite and metallic patches has been studied by calculating the stress intensity factor and the T-stress via 3D finite element method. The study of the out-of-plane bending role in repair of plates with single-sided patch is another aims of this research. The results showed that the higher stiffness of the composite patch leads to further reduction in stress intensity factor. It is found that in the studied specimens, the boron/epoxy patch has the better behavior compared with glass/epoxy one. Furthermore, using single-sided and double-sided patches leads to change in the T-stress value. The largest change achieved by the crack angle equals to 0 and the smallest on achieved by the crack angle equals to 45 degrees. Increasing the adhesive thickness leads to increasing the stress-intensity factor in repaired plate. Finally, it is found that the out-of-plane bending has the significant effect on behavior of repair with single-sided composite patch.

کلیدواژه‌ها English

Composite Patch
Stress Intensity Factor
Mixed mode
out-of-plane bending
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