TY - JOUR ID - 57796 TI - Numerical Investigation of Size and Structure Effect on Tensile Characteristics of Symmetric and Asymmetric CNTs JO - Journal of Ultrafine Grained and Nanostructured Materials JA - JUFGNSM LA - en SN - 2423-6845 AU - Zakeri, Mahnaz AU - Basiri, Omid AD - Aerospace Engineering Department, K.N.Toosi University of Technology, Tehran, 16765-3381, Iran Y1 - 2016 PY - 2016 VL - 49 IS - 1 SP - 1 EP - 10 KW - Chirality KW - Elasticity modulus KW - Equivalent continuum modeling KW - Poisson’s ratio DO - 10.7508/jufgnsm.2016.01.01 N2 - In this research, the influence of structure on the tensile properties of single- walled carbon nanotubes (CNTs) is evaluated using molecular mechanics technique and finite element method. The effects of diameter, length and chiral angle on elastic modulus and Poisson’s ratio of armchair, zigzag and chiral structures are investigated. To simulate the CNTs, a 3D FEM code is developed using the ANSYS commercial software. Considering the carbon-carbon covalent bonds as connecting load-carrying beam elements, and the atoms as joints of the elements, CNTs are simulated as space-frame structures. The atomic potentials are estimated using harmonic simple functions. The numerical results show that by increasing the diameter and length to a certain amount, the size effect on tensile behavior of modeled nanotubes is omitted. In fact, for nanotubes with diameter over 2 nm and length over 36.5 nm the chiral angle is the only effective factor on the tensile properties. Also, it is found that the structure has a little effect on the elasticity modulus, which is about 4%. However, Poisson’s ratio can be affected significantly with chiral angle. Asymmetric structures with angles θ <18˚ show higher Poisson’s ratio in comparison with the other structures, such that it can be 16% larger for little chirality CNTs than armchair. UR - https://jufgnsm.ut.ac.ir/article_57796.html L1 - https://jufgnsm.ut.ac.ir/article_57796_dbe0fc7ea5e006dfac8693096a0666b1.pdf ER -