علوم و فناوری کامپوزیت

پیش‌بینی مسیر رشد ترک در نمونه‌ی پلیمری دارای شیار V شکل تحت بارگذاری مرکب برشی- فشاری

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشیار، مهندسی مکانیک، دانشگاه تهران، تهران، ایران

2 دانشجوی دکترا ، مهندسی مکانیک، دانشگاه علم و صنعت ایران، تهران، ایران

3 استاد، دانشکده مهندسی مکانیک، دانشگاه علم و صنعت ایران، تهران، ایران

چکیده

مسیر رشد ترک از شیارهای V شکل نوک گرد در نمونه‌ی ‌دیسک برزیلی ساخته شده از پلیمر پلکسی گلاس تحت بارگذاری برشی-‌ فشاری به دو صورت تجربی و تئوری مورد بررسی قرار گرفته است. در ابتدا با انجام 18 آزمایش شکست، مسیر تجربی رشد ترک بر روی نمونه‌ی دیسک برزیلی دارای شیار V شکل (RV-BD) برای زوایای دهانه‌‌ی شیار مختلف و شعاع نوک شیار 5/0 میلی‌متر به دست آمده است. سپس با استفاده از دو روش المان محدود توسعه یافته بر مبنای مدل ناحیه‌ی چسبناک و روش گام به گام بر مبنای معیار حداکثر تنش محیطی، مسیر رشد ترک پیش‌بینی شده است. پیش‌بینی‌های حاصل از هر دو روش المان محدود توسعه یافته و روش گام به گام و همچنین نتایج آزمایشگاهی نشان می‌دهند که اگرچه شیار V شکل تحت بارگذاری برشی- فشاری قرار دارد، اما شکست آن در اثر تنش‌های کششی موجود در لبه‌ی شیار آغاز شده و تا مرز خارجی قطعه رشد می‌کند. تطابق کیفی مسیرهای پیش‌بینی شده توسط هر دو معیار با مسیر به دست آمده از مشاهدات آزمایشگاهی نشان دهنده‌ی توانایی هر دو روش در پیش‌بینی مسیر رشد ترک، برای شیارهای V شکل تحت بارگذاری برشی- فشاری می‌باشد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Crack growth trajectory prediction in V-notched polymeric specimen under combined compressive-shear loading conditions

نویسندگان [English]

  • Ali Reza Torabi 1
  • Bahador Bahrami 2
  • Majid Reza Ayatollahi 3

1 - Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran

2 - School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran

3 Professor, School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran

چکیده [English]

Crack growth trajectory in V-notched specimens is investigated by polymeric round-tip V-notched Brazilian disk (RV-BD) under combined compressive-shear loading conditions both experimentally and theoretically. First, the experimental fracture trajectory of RV-BD specimens is obtained by means of 18 fracture tests for various notch opening angles and 0.5 mm notch tip radius. Then, by utilizing two methods, namely the extended finite element method (XFEM) based on the cohesive zone model and the incremental method on the basis of the maximum tangential stress (MTS criterion), the fracture trajectory is predicted. Predictions of both the methods and also the experimental observations show that although the V-notch is under compressive-shear loading conditions, fracture initiates due to the tensile stresses at the notch border and propagates to the external boundary of the specimen. The graphical agreement of the two predicted trajectories with the experimental one demonstrates the ability of both methods in predicting the fracture trajectory for V-notches under compressive-shear loading conditions.

کلیدواژه‌ها [English]

  • Crack growth trajectory
  • V-notch
  • Extended finite element
  • Incremental method
مراجع
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علوم و فناوری کامپوزیت
دوره 4، شماره 3
آذر 1396
صفحه 337-346
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