مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

اندازه‌ گیری تجربی و اجزاء محدود تنش پسماند حاصل از جوشکاری ورق آلومینیومی و بررسی تأثیر آن بر روی مقادیر فرکانس طبیعی

نویسندگان
دانشگاه علم و صنعت ایران
چکیده
جوشکاری در صنایع هوافضا از اهمیت بسیاری برخوردار بوده و در اتصالات سازه ‏های هوافضایی کاربرد فراوانی دارد. از مشکلاتی که اغلب صنایع کشور با آن مواجه ‏اند تنش پسماند ناشی از فرآیند جوشکاری است. تنش پسماند در نواحی اطراف جوش می‏تواند باعث ایجاد و رشد ترک شود به همین علت شناخت و بررسی آن در سازه‏ های جوشکاری شده ضروری می‏باشد. روش‏های مختلفی برای اندازه ‏گیری تنش پسماند وجود دارد. در این مقاله به معرفی انواع روش‏های آزمایشگاهی و عددی در جهت تعیین تنش پسماند پرداخته شده است. سپس به کمک فرآیند جوش آرگون دو ورق آلومینیومی از جنس آلیاژ 6061-T6 به یکدیگر متصل شده‏ و تنش‏های پسماند حاصله به روش سوراخ کاری‏ به دست آمده است. جوشکاری به صورت دو پاسه صورت گرفته و توسط جوش نقطه‏ ای ابتدا، انتها و وسط خط جوش برای جلوگیری از جابجایی ورق‏ها به یکدیگر متصل شده ‏اند. همچنین فرآیند جوشکاری دو ورق آلومینیومی مذکور به صورت سه‏ بعدی در نرم‏ افزار اجزاء محدود آباکوس شبیه‏ سازی شده و تنش‏های پسماند استخراج شده‏ است. تمامی شرایط در تحلیل اجزای محدود مشابه شرایط جوشکاری در آزمایشگاه در نظر گرفته شده است، نتایج حاکی از دقت بالا در مدلسازی اجزای محدود فرآیند جوشکاری دارد. در نهایت تأثیر حضور تنش‏های پسماند در مقادیر فرکانس‏های طبیعی مورد بررسی قرار گرفته شده است.
کلیدواژه‌ها

موضوعات


عنوان مقاله English

Experimental measurements and finite element residual stress caused by welding aluminum sheets and investigating its effect on natural frequency values

نویسنده English

hussain gharehbaghi
IUST
چکیده English

Welding is very important in the aerospace industry and widely used in aerospace structures. One of the problems that most industries are facing is created residual stress by the welding process. Residual stresses in the surrounding areas of welding can cause cracks and crack growth so identify and evaluate of residual stresses in the welded structures is necessary. There are different methods for determining the residual stress. In this paper, the laboratory and numerical methods were presented for determining the residual stress. Then, the welding process of two aluminum sheets of 6061-T6 alloy has been done and the residual stresses have been obtained by drilling method. Welding is done in two passes and by spot welding the first, the end and the middle of the weld line are connected to prevent the sheets from moving. Also, the welding process of the two aluminum sheets was simulated in 3D in the ABAQUS finite element software and the residual stresses were extracted. All conditions in the finite element analysis are similar to the welding conditions in the laboratory. Results show high accuracy in the modeling of finite element processes in the welding process. Finally, the effect of residual stress in the value of natural frequencies is studied.

کلیدواژه‌ها English

Simulation of welding process
Crack Growth
Residual Stress
natural frequency
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