نانولوله‌های کربنی، آلوتروپ‌هایی از کربن با ویژگی‌های منحصر به فرد هستند. ساختار هر نانولوله با برداری به نام بردار کایرال توصیف می‌شود. در این مقاله، با دریافت طول نانولوله و دو مقدار ورودی m و n برای معرفی بردار کایرال در یک الگوریتم ساده، موقعیت اتم‌های کربن مشخص شده و هندسة کامل نانولوله شبیه‌سازی می‌گردد. سپس رفتار نمونه‌های گوناگونی از نانولوله‌ها با زوایای کایرال مختلف، با انجام تحلیل اجزای محدود، مورد بررسی قرار گرفته و خواص مکانیکی آنها به دست می‌آید. مقایسه نتایج مدل‌سازی حاضر با نتایج موجود در سایر مراجع و ناچیز بودن میزان خطا، نشان دهنده دقت مناسب الگوریتم حاضر در شـبیه‌سازی هندسة نانولوله‌ها است. نتایج نشان می‌دهد که نانولوله‌های کربنی در زوایای کایرال بین 17 تا 22 درجه بیشترین مدول کششی را دارند که مقدار آن در حدود TPa1 است.
Chirality Effects on Mechanical Properties of Single-Walled Carbon Nanotubes
نویسندگان [English]
Mahnaz Zakeri1؛ Mahdi shayanmehr2
چکیده [English]
Carbon nanotubes (CNTs) are carbon allotropes with unique characteristics. Structure of each nanotube is defined by a vector called chiral vector. In this paper, entering the nanotube length and two input values of m and n into a simple algorithm, the positions of carbon atoms are determined and the full geometry of nanotubes is depicted. Then, different kinds of nanotubes are simulated and their mechanical properties are determined using finite element method. Comparison of the results with previous results existing in the literature reveals good precision of this algorithm in simulating nanotubes geometry. The results show that CNTs have the most tensile modulus in chiral angles between 17-22 degree, which is about 1TPa.
مراجع
[1] Natsuki, T., Tantrakarn, K., and Endo, M. 2004. Prediction of elastic properties for single walled carbon nanotubes. Carbon 42: 39–45.
[2] Chopra, N., Benedict, L., Crespi, V., Cohen, M., Louie, S., and Zettl, A. 1995. Fully collapsed carbon nanotubes. Nature (London) 377: 135-138.
[3] Xiao, J.R., Gama, B.A., and Gillespie, JW. 2005. An analytical molecular structural mechanics model for the mechanical properties of carbon nanotubes. Int J. Solids and Struct 42: 3075–3092.
[4] Wu, Y., Zhang, X., Leung, AY.T., and Zhong, W. 2006. An energy-equivalent model on studying the mechanical properties of single-walled carbon nanotubes. Thin-walled Structures 44: 667–676.
[5] Rafii-Tabar, H. 2004. Computational modelling of thermo-mechanical and transport properties of carbon nanotubes. Physics Reports 390: 235–452.
[6] Lu, Q., and Bhattacharya, B. 2005. The role of atomistic simulations in probing the small scale aspects of fracture – a case study on a single-walled carbon nanotube. Engineering Fracture Mechanics 72: 2037–2071.
[7] Odegard, G.M., Gates, T.S., Nicholson, L.M., and Wise, K.E. 2002. Equivalent-continuum modeling of nano-structured materials. Comp Sci and Tech 62: 1869–1880.
[8] Li, C., and Chou, T.W. 2003. A structural mechanics approach for the analysis of carbon nanotubes. Int J. Solids and Struct 40: 2487–2499.
[9] Cornwell, C.F., and Wille, L.R. 1997. Elastic properties of single-walled carbon nanotubes in Compression. Solid State Commun 101(8): 555-558.
[10] Yao, N., and Lordi, V. 1998. Young’s modulus of single-walled carbon nanotubes. J. App Phys 84(4): 1939-1943.
[11] Zhang, H.W., Wang, J.B., and Guo, X. 2005. Predicting the elastic properties of single-walled carbon nanotubes. J. the Mech and Phys of Sol 53: 1929–1950.
[12] Gao, X.L., and Li, K. 2003. Finite deformation continuum model for single-walled carbon nanotubes. Int J. Solids and Struct 40: 7329–7337.
[13] Shokrieh, M.M., and Rafiee, R. 2010. On the tensile behavior of an embedded carbon nanotube in polymer matrix with nonbonded interphase region. Composite Structures 92: 647–652.
[14] Ayatollahi, M.R., Shadlou, S., and Shokrieh M.M. 2011. Multiscale modeling for mechanical properties of carbon nanotube reinforced nanocomposites subjected to different types of loading. Composite Structures 93: 2250–2259.
[15] Gogotsi, Y. Ed. 2006. Nanomaterials Handbook, London & New York: CRC Press.
[16] Gelin, B.R. 1994. Molecular modeling of polymer structures and properties, Germany: Hanser/Gardner Publishers.
[17] Wernik, J.M.,· and Meguid, S. A. 2011. Multiscale modeling of the nonlinear response of nano reinforced polymers. Acta Mech 217: 1-16.
[18] Inc, ANSYS. 2009. ANSYS Guide. Europe.
[19] Xiaoxing, Lu, and Zhong, Hu. 2012. Mechanical property evaluation of single-walled carbon nanotubes by finite element modeling. Composites: Part B 43: 1902–1913.
[20] Krishnan, A., Dujardin, E., Ebbesen, T.W., and Treacy, M.M.J. 1998. Young's modulus of single-walled nanotubes. Phys Rev B 58: 14013–9.
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