تحلیل تجربی و عددی اثر سه‌محوره‌ی تنش و زاویه‌ی لود بر شکست نرم آلیاژ تیتانیوم

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی مکانیک، دانشگاه تهران، تهران، ایران

چکیده

در این مقاله، تأثیر سه‌محوره تنش و زاویه لود بر شکل‌پذیری آلیاژ تیتانیوم درجه دو مورد بررسی قرار گرفته است. برای این تحقیق، چهار نمونه با هندسه‌های مختلف شامل نمونه‌های دمبلی‌شکل، شیاردار و دو نمونه برشی طراحی و ساخته شد. آزمایش کشش تک‌محوره در دمای محیط بر روی این نمونه‌ها انجام پذیرفت. از نمونه دمبلی‌شکل برای استخراج خواص مکانیکی آلیاژ تیتانیوم استفاده شد. شبیه‌سازی‌ها در نرم‌افزار آباکوس صورت گرفت و رفتار شکست نمونه‌ها تا پایان ناحیه پلاستیک تحلیل گردید. برای مطابقت نمودارهای نیرو-جابجایی، معادله ترکیبی سویفت و چند جمله‌ای مرتبه چهار به‌کار گرفته شد. مقایسه نتایج آزمایشات تجربی و شبیه‌سازی با آباکوس نشاندهنده تطابق خوبی بین نمودارها تا انتهای ناحیه پلاستیک است. در این تحقیق، سه‌محوره تنش برای چهار نمونه مختلف بین صفر تا 5/0 متغیر بود. به‌طور خاص، برای یکی از نمونه‌های برشی سه‌محوره تنش عدد صفر و برای دیگر نمونه برشی 0/2 به‌دست آمد. همچنین، سه‌محوره تنش برای نمونه دمبلی‌شکل و شیاردار به ترتیب 0/33 و 0/5 ثبت شد. نتایج به‌دست آمده نشان می‌دهند که نزدیکی سه‌محوره تنش به صفر منجر به شکست برشی در آزمایشات می‌شود و روند تغییرات زاویه لود نیز تأثیر متناظری بر کرنش شکست دارد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental and numerical analysis of the effect of stress triaxiality and Lode angle on ductile failure of Ti-6Al-4V alloy

نویسندگان [English]

  • Javad Ghafari
  • Mehdi Ganjiani
Faculty of Mechanical Engineering, University of Tehran, Tehran, Iran
چکیده [English]

In this article, the effect of stress triaxiality and Lode angle on the ductility of titanium grade 2 alloy has been investigated. For this research, four samples with different geometries, including Dog-bone samples, notched samples, and two shear samples, were designed and manufactured. A uniaxial tensile test at ambient temperature was performed on these samples. A Dog-bone sample was used to extract the mechanical properties of titanium alloy. The simulations were done in Abaqus software and the failure behavior of the samples was analyzed until the end of the plastic zone. To match the force-displacement diagrams, Swift's combined equation and fourth-order polynomial were used. Comparing the results of experimental tests and simulation with Abaqus shows a good agreement between the diagrams up to the end of the plastic zone. In this research, the stress triaxiality varied between zero and 0.5 for four different samples. Specifically, for one of the triaxial shear samples, the stress value was zero, and for the other shear sample, 0.2. Also, the stress triaxiality for Dog-bone and notched sample was recorded as 0.33 and 0.5 respectively.

کلیدواژه‌ها [English]

  • Ti-6AL-4V
  • Lode Angle
  • Stress Triaxiality
  • Fracture Strain
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