تحلیل تجربی و عددی تأثیر فشار هیدرواستاتیک در شکست نرم آلومینیوم 6-T6061

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده‌ی مهندسی مکانیک، دانشگاه تهران، تهران.

چکیده

در نوشتار حاضر از آزمون‌های تجربی و شبیه‌سازی عددی برای مطالعه‌ی سه‌محوره‌ی تنش، پارامتر زاویه‌ی لود، و تأثیر آن‌ها در رفتار شکست نرم آلومینیوم 6T-6061 استفاده ‌شده است. برای مطالعه‌ی مقادیر سه‌محوره‌ی تنش منفی، به‌جای انجام آزمون دومحوره، از آزمون‌های تک‌محوره‌ی کششی و فشاری بر روی هندسه‌های خاص استفاده شده است؛ که شامل: نمونه‌ی دمبلی و نمونه‌های مستطیلی حاوی حفره‌ی بیضوی با انحنا بوده‌اند. مقادیر سه‌‌محوره‌ی تنش منفی در بازه‌ی 355/0- تا 555/0- به‌دست آمده‌اند. با مقایسه‌ی نتایج آزمون‌های تجربی و شبیه‌سازی، می‌توان نتیجه گرفت که هر دو روش مقادیر کرنش شکست، مطابقت یکسانی را پیش‌بینی می‌کنند. براساس کانتورهای آسیب، ناحیه‌ای که شکست در آن آغاز شده است، با نواحی دارای بیشترین کرنش خمیری هم‌پوشانی داشته است، هر چند مقدار آن تحت تأثیر مقدار تنش سه‌محوره و زاویه‌ی لود بوده است. براساس داده‌های به‌دست‌آمده مشاهده شده است که در تنش سه‌محوره‌های مثبت، کرنش شکست ابتدا افزایش و سپس کاهش یافته است، در حالی ‌که در تنش سه‌محوره‌های منفی، این روند برعکس بوده و کرنش شکست، ابتدا کاهش و سپس افزایش پیدا کرده است.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Experimental and Numerical Analysis of Hydrostatic Pressure in Ductile Fracture of AL-6061T6

نویسندگان [English]

  • Mohsen Mansouri
  • Mehdi Ganjiani
Faculty of Mechanical Engineering, University of Tehran, Iran.
چکیده [English]

This study investigates the effects of stress triaxiality and the Lode angle parameter on the ductile fracture behavior of aluminum alloy 6061-T6 using experimental tests and numerical simulations. To analyze negative triaxiality conditions, compression tests were performed on specially designed specimens, including a standard dog-bone and rectangular samples with elliptical holes of varying curvature. The obtained negative triaxiality values ranged from −0.355 to −0.555. A good agreement between experimental and numerical results confirms the reliability of the adopted approach. The fracture initiation zones coincide with regions of maximum plastic strain, strongly influenced by triaxiality and Lode angle. The results indicate that fracture strain depends nonlinearly on triaxiality: for positive triaxiality it first increases then decreases, while the reverse trend is observed under negative triaxiality. These findings enhance the understanding of how stress-state parameters influence ductile fracture mechanisms and can be applied to improve the design and durability of metallic components in engineering applications.

کلیدواژه‌ها [English]

  • Stress triaxiality
  • fracture strain
  • normalized lode angle
  • ductile fracture

مراجع

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