نوع مقاله : مقاله پژوهشی

نویسنده

استادیار، مهندسی مکانیک، دانشگاه شهید بهشتی، تهران .

10.22068/jstc.2022.555832.1791

چکیده

در این مقاله با توجه به اهمیت پدیده پل‌زنی ترک حین رشد تورق در کامپوزیت‌های لایه‌ای تحت مود ترکیبی I/II و به منظور فهم فیزیک مسئله پل‌زنی ترک، ابتدا با انجام آزمایش‌های شکست بین لایه‌ای بر روی نمونه‌های‌ کامپوزیتی و مشاهده سطوح شکست و ناحیه آسیب جلوی نوک تورق بر روی لبه نمونه‌ها با استفاده از میکروسکوپ الکترونی روبشی، به شناسایی و معرفی مهم‌ترین مایکرومکانیزم‌های درگیر حین پدیده پل‌زنی الیاف پرداخته می‌شود. در ادامه، با توجه به پیچیدگی مدل‌های موجود برای پیش‌بینی قوانین پل‌زنی در تورق کامپوزیت‌های لایه‌ای و دشواری تعیین پارامترهای متعدد موجود در آن‌ها، یک روش تقریبی جدید برای تعیین قانون پل‌زنی بر اساس یک مدل پیچیده‌تر مبتنی بر فیزیک ارائه شده است. در این روش، با حفظ مبنای فیزیکی مسئله و از طریق جایگذاری تقریب‌های ساده در توصیف پل‌زنی، به استخراج قوانین پل‌زنی پرداخته شده است. مزیت اصلی روش ارائه شده، دستیابی به قوانین پل‌زنی با استفاده از روابط ساده‌تر و با تعداد پارامترهای موردنیاز کمتر است. در نهایت به منظور ارزیابی صحت و دقت روش، رفتار کشش- جدایش ناحیه پل‌زنی پیش‌بینی شده توسط قانون پل‌زنی تقریبی ارائه شده با منحنی‌های کشش- جدایش تجربی در نسبت ترکیب مودهای مختلف مقایسه خواهد شد.

کلیدواژه‌ها

عنوان مقاله [English]

A novel approximate method for determining mixed mode I/II bridging law of laminated composites

نویسنده [English]

  • Zahra Daneshjoo

Faculty of Mechanical Engineering and Energy, Shahid Beheshti University, Tehran, Iran.

چکیده [English]

This paper has been presented according to the importance of crack bridging in mixed mode I/II delamination of laminated composites and it is aimed to understand the physics of crack bridging. Firstly, the most important micro-mechanisms involved during fiber bridging are introduced. To do this, interlaminar fracture tests have been performed on composite specimens. Also, the fracture surfaces and the damage zone on the edge of the specimens have been observed using a scanning electron microscope (SEM). In the following, due to the complexity of the existing bridging models and the difficulty of determining their various parameters, a novel approximate method has been presented. In this method, which is based on a more complex physics-based model, the bridging laws are extracted by preserving the physics of the problem and considering simple approximations. The main advantage of the proposed method is the achievement of bridging laws using simpler relationships with fewer required parameters. Finally, the validity of the method has been evaluated through a comparison of the traction-separation behavior predicted by the proposed approximate bridging laws with the experimental traction-separation curves in different mode mixities.

کلیدواژه‌ها [English]

  • Bridging law
  • Laminated composite
  • Fracture process zone
  • Delamination
  • Mixed mode I/II loading
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