بررسی رشد دو ترک پادمتقارن در ورق براثر کشش لبه ها با سرعت های مختلف با استفاده از تئوری پری داینامیک

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی هوافضا، دانشگاه سمنان، سمنان ، ایران

2 دانشکده مهندسی مکانیک، دانشگاه گیلان، رشت، ایران

چکیده

با وجود توسعه مدل‌های پیش بینی شروع و رشد ترک، این موضوع هنوز یکی از چالش‌های عمده در مکانیک محیط‌های پیوسته است. مشکل اصلی در فرمول‌بندی ریاضی این موضوع به این علت به وجود می‌آید که فرض می‌شود جسم پس از تغییر شکل هنوز محیط پیوسته باقی می‌ماند. بنابراین، ساختار ریاضیاتی مساله با به وجود آمدن یک ناپیوستگی )مانند ترک و شکست( دچار مشکل می‌شود. این اتفاق بدین دلیل رخ می‌دهد که تئوری کلاسیک از معادلات دیفرانسیل با مشتقات جزئی برای تشریح فضای مادی استفاده می‌کند و این مشتقات جزئی در محل ناپیوستگی تعریف نشده است. برای غلبه بر این محدودیت، روش پری داینامیک برای مدل سازی مسائل شامل ناپیوستگی معرفی شده که در آن ناپیوستگی هایی مانند ترک و شکست در سازه به عنوان نوعی دیگر از تغییر شکل در نظر گرفته می‌شود. در این مقاله مساله رشد ترک در ورقی با دو ترک پادمتقارن تحت کشش بررسی شده و پس از صحه گذاری نتایج با مطالعات موجود، اثر سرعت اعمال بار کششی بر نحوه رشد ترک مورد بررسی قرار گرفته است. نتایج این تحقیق نشان می‌دهد که روش پری داینامیک توانایی بالایی در شبیه‌سازی رفتار سازه با هر سرعت بارگذاری را دارد و سرعت اعمال بار تاثیر مستقیمی بر نحوه رشد ترک و ایجاد پدیده چند شاخه شدن ترک دارد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

A Peridynamic Study on Crack Growth in Plates with Two Anti-symmetric Cracks under Various Tensile Velocities

نویسندگان [English]

  • M. Shakouri 1
  • S. R. Kazemi 2
1 Department of Aerospace Engineering, Semnan University, Semnan, Iran
2 Department of Mechanical Engineering, University of Guilan, Guilan, Iran
چکیده [English]

 Despite the development of some advanced concepts in fracture mechanics during recent decades, the prediction of crack initiation and its growth in materials is still a major challenge. The main difficulty is because of the continuum based mathematical formulation, which assumes that a body remains continuous as it deforms. In fact, the classical theory is formulated using spatial partial differential equations. This presents a characteristic limitation to the classical theory, as the spatial derivatives in the governing equations lose their meaning due to the presence of a discontinuity, such as a crack. To overcome this problem, Peridynamic theory could be used to improve the analysis of cracked structures. Basically, the peridynamic theory is a reformulation of the equation of motion in solid mechanics that is better suited for modeling bodies with discontinuities, such as cracks. The theory uses spatial integral equations that can be applied to a discontinuity. The present study uses this approach to study the effects of applying tensile loads on crack paths in a plate with two parallel initial cracks located in an anti-symmetric manner. The results are compared with other investigations and it is shown that the velocity of applying load has significant effect on crack path and branching.

کلیدواژه‌ها [English]

  • Peridynamic Theory
  • Crack Growth
  • Branching
  • Loading rate
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