تحلیل عددی رفتار مکانیکی پلیمرهای نیمه‌بلوری از دیدگاه مکانیک آسیب محیط پیوسته

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی مکانیک، دانشگاه تهران

2 دانشگاه تهران، دانشکده مهندسی مکانیک

چکیده

در پژوهش حاضر، برای تحلیل رفتار پلیمرهای نیمه‌بلوری، با استفاده از دیدگاه مکانیک آسیب محیط پیوسته، یک مدل مکانیکی ارائه شده است. در این مدل، یک نقطه مادی از پلیمر نیمه‌بلوری به صورت مجموعی از توده‌ها، شامل دو فاز بلوری و بی‌شکل و صفحه مرزی فازها درنظر گرفته شده و معادلات اساسی هر یک از فازها تشریح شده است. سپس الگوریتمی عددی برای حل معادلات اساسی هر فاز به صورت مرحله به مرحله ارائه شده است. همچنین با استفاده از میانگین گیری حجمی، رفتار کلی ماده برحسب رفتار هرکدام از فازها مشخص گردیده است. به دلیل در دسترس بودن پارامترهای مادی برای پلی‌اتیلن، رفتار این ماده مورد تحلیل قرار گرفته است. نتایج عددی بدست آمده با نتایج مدل‌ها و آزمایشات قبلی مقایسه شده است، پس از تأیید اعتبار مدل ارائه شده، تأثیر پارامترهای نرخ آسیب فاز بلوری، پارامتر رهایی، نرخ آسیب فاز بی‌شکل، آسیب اشباع، مدول برشی لاستیکی و مقاومت فاز بی‌شکل بر رفتار پلی‌اتیلن مورد بررسی قرار گرفته است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Analysis of Mechanical Behavior of Semi-Crystalline Polymers Based on Continuum Damage Mechanics

نویسندگان [English]

  • Hadi Mehdipour 1
  • Mahdi Ganjiani 2
1 M.Sc student, University of Tehran
2 Faculty of Mechanical Engineering, University of Tehran
چکیده [English]

In the current study, semi-crystalline polymers and their properties are introduced, and then a mechanical model is precisely presented in order to predict the behavior of these materials. In this model, a material point of the semi-crystalline polymer is considered as an aggregate of inclusions of two phases, namely, the crystalline and the amorphous phase, with the interface plane of these two phases. Constitutive equations of each phase are demonstrated. A numerical algorithm is presented for solving the constitutive equations of each phase, in stages. Moreover, the general behavior of the material is determined in terms of each phase behavior using volume averaging. Because of the availability of the material parameters for polyethylene, this material has been taken into account. Obtained numerical results are reported and compared to that of previous models. After supporting the validity of the presented model, the effect of some material parameters including crystalline phase damage rate, release parameter, amorphous phase damage rate, saturation damage, rubber shear modulus, and amorphous phase strength on polyethylene behavior has been discussed in details.

کلیدواژه‌ها [English]

  • Continuum Damage Mechanics
  • Semi-crystalline polymers
  • Numerical algorithm
  • Polyethylene
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