تحلیل رفتار کمانشی نانولوله‌های کربنی با استفاده از مکانیک مولکولی ساختاری

نوع مقاله : مقاله پژوهشی

نویسندگان

1 عضو هیات علمی / دانشکدة مهندسی هوافضا، دانشگاه صنعتی خواجه نصیرالدین طوسی

2 دانشجوی کارشناسی ارشد / دانشکدة مهندسی هوافضا، دانشگاه صنعتی خواجه نصیرالدین طوسی

چکیده

بروز پدیدة کمانش در شرایط متنوع بارگذاری به ناپایداری سازه می‌انجامد. اساساً بار بحرانی کمانش به عواملی چون هندسه، اندازه، نوع بار و شرایط مرزی بستگی دارد. هدف از نگارش این مقاله، مطالعة اثر ساختار بر رفتار کمانشی نانولوله‌های کربنی است. برای اینکه اثر زاویة کایرال مستقل از اثر اندازه بررسی شود، از هندسه‌هایی با ابعاد برابر و کایرالیتة متفاوت استفاده شده است. برای شبیه‌سازی پیوندهای شیمیایی بین اتم‌های کربن، انرژی پیوند کووالانت کربن - کربن به‌روش مکانیک مولکولی با المان تیر مدل می‌شود. همچنین مختصات گره‌ها به‌وسیلة الگوریتمی ساده تعیین می‌گردد. سپس اثر کایرالیته بر بار کمانش محوری و پیچشی برای انواع ساختارها، با استفاده از روش اجزای محدود تحلیل می‌شود. نتایج مقاله نشان می‌دهد که زاویة‌ کایرال اثر قابل توجهی بر بار کمانش محوری ندارد. اما در بارگذاری پیچشی، ساختار نانولوله تأثیر قابل توجهی بر پایداری آن دارد؛ به‌طوری‌که در شرایط کمانش پیچشی، ساختارهای کایرال ممکن است ضعیف‌تر یا قوی‌تر از ساختارهای متقارن عمل کنند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Analysis of buckling behavior of CNTs using molecular structural mechanics

نویسندگان [English]

  • Mahnaz Zakeri 1
  • Omid Afzalnazhad 2
چکیده [English]

Buckling phenomena in different loading conditions, will lead to structural instability. Critical buckling load is dependent to factors such as geometry, size, load type, and boundary conditions. The aim of this paper is to study of the structure effect on the buckling behavior of carbon nanotubes (CNTs). In order to investigate the effect of chiral angle independent from size effects, all structures are used with the same dimensions but different chiralities. To simulate the chemical bonds between carbon atoms, carbon-carbon covalent bond energy is modeled using molecular mechanics theory and beam element. Coordinates of the nodes are determined using a simple algorithm. Then, chirality effect on axial and torsional buckling load is analyzed using finite element method for different structures. The results of this research show that the chiral angle has no significant effect on critical axial buckling load. However, CNT's structure has considerable influence on the stability. Chiral structures can be weaker or stronger against torsional buckling than symmetric structures.

کلیدواژه‌ها [English]

  • Equivalent Continuum Technique
  • chirality
  • Buckling
  • clock-wise and anti-clock-wise torsion
[1] Iijima, S. Helical microtubules of graphitic carbon, nature, Vol. 354, No. 6348, 1991, pp. 56-58.
[2] Asadi, E., M. FarhadiNia. Vibrational study of laminated composite plates reinforced by carbon nanotubes, Modares Mechanical Engineering, Vol. 14, No. 3, 2014, pp. 7-16.
[3] O'Connell, M., Carbon nanotubes: properties and applications, United States of America: CRC Press Taylor & Francis Group, 2006.
[4] Shima, H. “Buckling of carbon nanotubes: a state of the art review.” Carbon Nanotubes: Synthesis, Characterization and Applications, Vol. 5, 2011, pp. 47-84.
[5] Han Q., G. Lu. “Torsional buckling of a double-walled carbon nanotube embedded in an elastic medium.” European Journal of Mechanics-A/Solids, Vol. 22, No. 6, 2003, pp. 875-883.
[6] Wang, X., H. Yang, K. Dong. “Torsional buckling of multi-walled carbon nanotubes.” Materials Science and Engineering: A, Vol. 404, No. 1, 2005, pp. 314-322.
[7] Chang, T., G. Li, X. Guo. “Elastic axial buckling of carbon nanotubes via a molecular mechanics model.” Carbon, Vol. 43, No. 2, 2005, pp. 287-294.
[8] Cao, G., X. Chen. “The effects of chirality and boundary conditions on the mechanical properties of single-walled carbon nanotubes.” International Journal of Solids and Structures, Vol. 44, No. 17, 2007, pp. 5447-5465.
[9] Zhang, Y., V. Tan, C. Wang. “Effect of strain rate on the buckling behavior of single-and double-walled carbon nanotubes.” Carbon, Vol. 45, No. 3, 2007, pp. 514-523.
[10] Xiaohu, Y., H. Qiang. “Investigation of axially compressed buckling of a multi-walled carbon nanotube under temperature field.” Composites science and technology, Vol. 67, No. 1, 2007, pp. 125-134.
[11] Sun, C., K. Liu. “Combined torsional buckling of multi-walled carbon nanotubes coupling with axial loading and radial pressures.” International journal of solids and structures, Vol. 45, No. 7, 2008, pp. 2128-2139.
[12] Yao, X., Q. Han, H. Xin. “Bending buckling behaviors of single-and multi-walled carbon nanotubes.” Computational Materials Science, Vol. 43, No. 4, 2008, pp. 579-590.
[13] Ghorbanpour Arani, A., R. Rahmani, A. Arefmanesh. “Elastic buckling analysis of single-walled carbon nanotube under combined loading by using the ANSYS software.” Physica E: Low-dimensional Systems and Nanostructures, Vol. 40, No. 7, 2008, pp. 2390-2395.
[14] Kang, Z., M. Li, Q. Tang. “Buckling behavior of carbon nanotube-based intramolecular junctions under compression: Molecular dynamics simulation and finite element analysis.” Computational Materials Science, Vol. 50, No. 1, 2010, pp. 253-259.
[15] Ansari, R., S. Rouhi. “Atomistic finite element model for axial buckling of single-walled carbon nanotubes.” Physica E: Low-dimensional Systems and Nanostructures, Vol. 43, No. 1, 2010, pp. 58-69.
[16] Saavedra Flores, E., S. Adhikari, M. Friswell, F. Scarpa. “Hyperelastic axial buckling of single wall carbon nanotubes.” Physica E: Low-dimensional Systems and Nanostructures, Vol. 44, No. 2, 2011, pp. 525-529.
[17] Ansari, R., S. Sahmani, H. Rouhi. “Axial buckling analysis of single-walled carbon nanotubes in thermal environments via the Rayleigh–Ritz technique.” Computational Materials Science, Vol. 50, No. 10, 2011, pp. 3050-3055.
[18] Ghavamian, A., A. Öchsner. “Numerical investigation on the influence of defects on the buckling behavior of single-and multi-walled carbon nanotubes.” Physica E: Low-dimensional Systems and Nanostructures. Vol. 46, 2012, pp. 241-249.
[19] Şimşek, M., H. Yurtcu. “Analytical solutions for bending and buckling of functionally graded nanobeams based on the nonlocal Timoshenko beam theory.” Composite Structures, Vol. 97, 2013, pp. 378-386.
[20] Tserpes, K., P. Papanikos. “Finite element modeling of single-walled carbon nanotubes.” Composites Part B: Engineering, Vol. 36, No. 5, 2005, pp. 468-477.
[21] Lu, X., Z. Hu. “Mechanical property evaluation of single-walled carbon nanotubes by finite element modeling.” Composites Part B: Engineering, Vol. 43, No. 4, 2012, pp. 1902-1913.
[22] Pantano, A., D. M Parks, M. C. Boyce. “Mechanics of deformation of single-and multi-wall carbon nanotubes.” Journal of the Mechanics and Physics of Solids, Vol. 52, No. 4, 2004, pp. 789-821.
[23] Meo, M., M. Rossi. “Prediction of Young’s modulus of single wall carbon nanotubes by molecular-mechanics based finite element modelling.” Composites Science and Technology, Vol. 66, No. 11, 2006, pp. 1597-1605.
[24] Wernik, J., S. Meguid. “Multiscale modeling of the nonlinear response of nano-reinforced polymers.” Acta Mechanica, Vol. 217, No. 1-2, 2011, pp. 1-16.
[25] Li, C., T.-W. Chou. “A structural mechanics approach for the analysis of carbon nanotubes.” International Journal of Solids and Structures, Vol. 40, No. 10, 2003, pp. 2487-2499.
[26] Ansys Software Help,12.0 Release, SAS IP, Inc, 2009.
[27] Zakeri, M., O. Basiri. “Estimation of shear and bending moduli for carbon nanotubes with chirral structures.” Modares Mechanical Engineering, Vol. 13, No. 14, 2014, pp. 56-67.
[28] Chen, L., Q. Zhao, H. Zhang. “Axial buckling behavior of single-walled carbon nanotubes with finite element modeling”, in Proceeding of, IEEE, NEMS, 2010, pp. 276-279.