مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

بررسی رفتار مکانیکی صفحات نانو گرافن کامل و یا با نقص ساختاری با استفاده از روش المان محدود مرزی مقیاس شده

نویسندگان
1 گروه مهندسی مکانیک،پردیس دانشگاه صنعتی اصفهان،ایران،اصفهان
2 استادیار/ دانشگاه صنعتی اصفهان
چکیده
در این مقاله برای اولین بار با استفاده از روش نیمه تحلیلی المان محدود مرزی مقیاس شده ، صفحات نانو گرافن کامل و همچنین با نقص ساختاری شبیه سازی شده و رفتار مکانیکی آن مورد بررسی قرار گرفت. در این تحلیل، پیوند اتمی بین اتم های کربن با یک میله با سطح مقطع دایره‌ای مدل سازی و سپس روابط المان محدود مرزی مقیاس شده بر مبنای هندسه مدل طرح ریزی شد. مقایسه نتایج بدست آمده از روش المان محدود مرزی مقیاس شده با دینامیک مولکولی نشان داد که این روش تحلیل می تواند با دقت بالا به عنوان یک روش محیط پیوسته در تحلیل مکانیکی صفحات نانو گرافن کامل و یا با نقص ساختاری استفاده گردد. وجود نقص ساختاری به میزان قابل توجه‌ای از استحکام و کرنش شکست صفحه نانوگرافن می‌کاهد به‌گونه‌ای که تنش شکست بیش از 34% و کرنش شکست بیش از 50% کاهش می‌یابد. همچنین در صورتی که به جای المان میله ، صفحه نانو گرافن یک صفحه محیط پیوسته در نظر گرفته شده و به منظور ایجاد یک هندسه یکسان با مسائل دارای المان میله، محیط عاری از ماده با المان های دارای مدول الاستیسته صفر شبیه‌سازی گردد، نتایج دارای دقت لازم مشابه نتایج با المان میله نخواهد بود.
کلیدواژه‌ها

موضوعات


عنوان مقاله English

Investigation of mechanical behavior of perfect nano-garphene sheets and defected ones by Scaled boundary finite element method

نویسندگان English

Mehrdad Honarmand 1
Mehran Moradi 2
1 Mechanical Engineering group, Pardis College,Isfahan University of Technology,Isfahan,iran
چکیده English

For the first time in this paper, by using semi-analytical scaled boundary finite element method (SBFM), a perfect nano garphene sheet or defected ones were simulated and their mechanical behavior had been investigated. In this analysis, the atomic carbon bonds were modeled by simple bar elements with circular cross- sections and then the scaled boundary finite element relations were formulated based on the geometry of the model. The obtained results from SBFM were compared to those obtained from molecular dynamic method which showed that the SBFM can be used as a continuum mechanics model with high accuracy in mechanical analysis of both perfect and defected nano graphene sheets. Existence of structural defects in nano grapheme sheets decrease the strength as well as fracture strain in a considerable manner. It can be noted that in a defected nano grapheme sheet, the fracture stress decreases more than 34% while fracture strain decreases more than 50%. In the cases that instead of using bar elements, whole area is considered as a continuum sheet and in order to obtain a similar geometry to those problems have bar elements, no material zone be modeled by zero elastic properties, the results show considerable errors.

کلیدواژه‌ها English

Scaled boundary finite element
Nano graghene sheets
Defected
mechanical behavior
molecular dynamics
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