پ۲۹۳۸۲
per
رشد ترک خزشی در مخزن استوانه ای از جنس AL7075-T6 تحت بارگذاری پیچشی و گرادیان درجه حرارت
فرید مجرد حیدرلو
مکانیک
۱۴۰۲
۶۷ص.
سی دی
دکتری
مهندسی مکانیک گرایش طراحی کاربردی
۱۴۰۲/۰۶/۳۱
طی سال های اخیر با توجه به کاربرد وسیع مواد فلزی و نیز اهمیت تحلیل ایمنی و افزایش طول عمر اجزای مکانیکی تحت بارگذاری های مختلف از جمله بارگذاری پیچشی، خمشی و فشاری مورد توجه محققان بسیاری قرار گرفته است. از میان کاربردهای آلیاژ های آلومینیومی می‌توان در صنایع نظامی و غیر نظامی به بدنه هواپیما، بدنه راکت، اتاقک ایستگاه فضایی وکشتی‌سازی اشاره کرد. بدنه‌ی این سازه‌ها در غالب موارد به علت مراحل تولید یا استفاده‌ی طولانی دچار ترک می‌شوند. در نتیجه ضروری است رفتار خزشی ترک در بدنه‌ی این سازه‌ها مورد توجه قرار گیرد چرا که عامل تنش موضعی بسیار زیاد و درجه حرارت بالا با گرادیان شدید موجب رشد سریع ترک در بدنه خواهد شد. همچنین به دلیل اینکه ساختار مخزنی بیشتر سازه ها در معرض پیچش و فشار و گرادیان درجه حرارت بالا قرار می گیرند، بررسی خواص مکانیکی آن ها از نظر رفتار خزشی از اهمیت بالایی برخوردار است. در اين مطالعه، ابتدا هندسه مورد نظر در نرم افزار آباکوس شبیه سازی گردید و سپس هندسه ترک مورد نظر روی سیلندر ایجاد شد و نرخ رشد ترک با استفاده از روش مکانیک شکست محیط پیوسته (CDM) تخمین زده شد. در نهایت، تاثیر پارامترهای مختلف هندسی یا مادی نظیر فشار داخلی، بار پیچشی، شعاع و ضخامت دیواره سیلندر، عمق و طول ترک و وجود گرادیان درجه حرارت در طول دیواره سیلندر روی پارامترC* و نتیجه نرخ رشد ترک مورد بررسی قرار گرفت و نتایج در قالب نمودارهای مختلف ارائه شده است.
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International journal of pressure vessels and piping, 2011. 88(11-12): p. 452-464.Last name: Mojarrad Heydarlo Name: FaridThesis title: Creep crack growth under torsional loading and temperature gradient in an AL7075-T6 cylindrical vesselSupervisor: Dr. Farid Vakili-TahamiAdvisor: Dr. Hassan BiglariDegree: Master of Sciences Major: Mechanical EngineeringUniversity: University of TabrizFaculty: Mechanical Engineering Graduation date: Pages: 67Keywords: Creep crack growth, Torsional, Elliptical crack, Multiple cracks interaction, C* Aluminum 7075-T6 Abstract:In recent years, due to the wide application of metal materials and the importance of safety analysis and increasing the life of mechanical components under various loadings, including torsional, bending and compressive loading, it has been the focus of many researchers. Among the applications of aluminum alloys in military and civilian industries, we can mention aircraft body, rocket body, space station cabin and shipbuilding. In most cases, the body of these structures suffers from cracks due to the production process or long use. As a result, it is necessary to pay attention to the creep behavior of the crack in the body of these structures, because the factor of very high local stress and high temperature with a strong gradient will cause the rapid growth of the crack in the body. Also, due to the fact that the tank structure of most of the structures are exposed to twisting and pressure and high temperature gradient, checking their mechanical properties in terms of creep behavior is of great importance. In this study, the desired geometry was first simulated in Abaqus software, and then the desired crack geometry was created on the cylinder, and the crack growth rate was estimated using the Continuous Medium Fracture Mechanics (CDM) method. Finally, the influence of various geometric or material parameters such as internal pressure, torsion, radius and thickness of the cylinder wall, depth and length of the crack and the presence of temperature gradient along the cylinder wall on the C* parameter and the result of the crack growth rate were investigated and the results were presented in the format Various charts are provided.
Creep crack growth under torsional loading and temperature gradient in an AL7075-T6 cylindrical vessel
مجرد حیدرلو،
فرید
تهیه کننده
وکیلی تهامی،
بیگلری،
فرید
حسن
استاد راهنما
استاد مشاور
تبریز
