Investigating the Effect of Stone-Wales Defect on Young Modulus of Armchair Single Wall Carbon Nanotube Using Molecular Dynamics Simulation

Author(s):  
H. Rezaei Nejad ◽  
M. Ghasemi ◽  
A. Shahabi ◽  
S. M. Mirnouri Langroudi

Effect of Stone-Wales percentage defect on effective elastic modulus of single-walled carbon nanotubes (SWCNT) is investigated. The Stone-Wales defect is a crystallographic defect that happens in nanotubes and is believed to affect the nanotubes mechanical properties. In order to calculate the mechanical properties of SWCNTs under axial tension, molecular dynamics (MD) simulations using the Morse potential is performed. An in house FORTRAN code is developed and utilized. The Young’s modulus of the perfect SWCNTs and those with different defect percentage is obtained using the classical elasticity theory. It is observed that for low percentage of defect (less than 8%) as the diameter increases the Young’s modulus of SWCNTs slightly increases. However, for high percentage of defect (more than 8%) as diameter increases the Young modulus clearly decreases.

Author(s):  
Mohsen Motamedi ◽  
AH Naghdi ◽  
SK Jalali

Composite materials have become popular because of high mechanical properties and lightweight. Aluminum/carbon nanotube is one of the most important metal composite. In this research, mechanical properties of aluminum/carbon nanotube composite were obtained using molecular dynamics simulation. Then, effect of temperature on stress–strain curve of composite was studied. The results showed by increasing temperature, the Young’s modulus of composite was decreased. More specifically increasing the temperature from 150 K to 620 K, decrease the Young’s modulus to 11.7%. The ultimate stress of composite also decreased by increasing the temperature. A continuum model of composite was presented using finite element method. The results showed the role of carbon nanotube on strengthening of composite.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Liang Zhao ◽  
Mahyuddin K. M. Nasution ◽  
Maboud Hekmatifar ◽  
Roozbeh Sabetvand ◽  
Pavel Kamenskov ◽  
...  

AbstractIn the present study, the improvement of mechanical properties of conventional concretes using carbon nanoparticles is investigated. More precisely, carbon nanotubes are added to a pristine concrete matrix, and the mechanical properties of the resulting structure are investigated using the molecular dynamics (MD) method. Some parameters such as the mechanical behavior of the concrete matrix structure, the validation of the computational method, and the mechanical behavior of the concrete matrix structure with carbon nanotube are also examined. Also, physical quantities such as a stress–strain diagram, Poisson's coefficient, Young's modulus, and final strength are calculated and reported for atomic samples under external tension. From a numerical point of view, the quantities of Young's modulus and final strength are converged to 35 GPa and 35.38 MPa after the completion of computer simulations. This indicates the appropriate effect of carbon nanotubes in improving the mechanical behavior of concrete and the efficiency of molecular dynamics method in expressing the mechanical behavior of atomic structures such as concrete, carbon nanotubes and composite structures derived from raw materials is expressed that can be considered in industrial and construction cases.


RSC Advances ◽  
2020 ◽  
Vol 10 (52) ◽  
pp. 31318-31332
Author(s):  
Md. Habibur Rahman ◽  
Shailee Mitra ◽  
Mohammad Motalab ◽  
Pritom Bose

Variations of fracture stress and Young’s modulus of graphene with the concentration of silicon doping.


2011 ◽  
Vol 697-698 ◽  
pp. 487-490
Author(s):  
M.Y. Zhou ◽  
Yan Ling Tian ◽  
Z. Ren ◽  
H.Y. Zheng ◽  
R.B. Wei

Molecular dynamics (MD) simulations were used to investigate the elastic properties of carbon nanotubes (CNTs). Displacements were loaded to CNTs on the tension deformation simulations. In order to better understand the relationship between Young’s modulus and the structure of the CNTs, different chiralities and diameters were involved. It is found that the Young’s modulus will be no more sensitive as in the single-walled carbon nanotubes (SWCNTs) with increasing walls. The tension deformation results also indicate that SWCNTs have better elastic property compared to multi-walled carbon nanotubes (MWCNTs).


2007 ◽  
Vol 14 (04) ◽  
pp. 661-665 ◽  
Author(s):  
ZHENYU YANG ◽  
YA-PU ZHAO

Size-dependent elastic properties of Ni nanofilms are investigated by molecular dynamics (MD) simulations with embedded atom method (EAM). The surface effects are considered by calculating the surface relaxation, surface energy, and surface stress. The Young's modulus and yield stress are obtained as functions of thickness and crystallographic orientation. It is shown that the surface relaxation has important effects on the the elastic properties at nanoscale. When the surface relaxation is outward, the Young's modulus decreases with the film thickness decreasing, and vice versa. The results also show that the yield stresses of the films increase with the films becoming thinner. With the thickness of the nanofilms decreasing, the surface effects on the elastic properties become dominant.


2005 ◽  
Vol 891 ◽  
Author(s):  
Hyuk Soon Choi ◽  
Taebum Lee ◽  
Hyosug Lee ◽  
Jongseob Kim ◽  
Ki-Ha Hong ◽  
...  

ABSTRACTThe interests of low-k dielectric materials to reduce capacitance in multilevel metal interconnects of integrated circuits are well known in the semiconductor industry. Mechanical properties of low-k film are currently the main issues. Improved hardness and modulus are desirable because, when building a multilayered stack and doing sequential processing, films go through chemical mechanical planarization. In this proceeding, we reports the Young's moduli of the typical low k materials, and the effects of various factors for Young's moduli of materials, such as, structures of precursors, density, and porosity. Using atomistic molecular dynamics simulation with experimental measurements, the Young's moduli of films of amorphous silicon oxide in which 25% of Si-O-Si chains were replaced by Si-(CH3 H3C)-Si, Si-CH2-Si, Si-(CH2)2-Si, Si-(CH2)3-Si, Si-(CH2)4-Si, Si-(CH2)6-Si, were measured and analyzed. The predicted trends of Young's moduli of films formed by above precursors are in good consistent with those observed from experiments. The Young's moduli of materials are largely dependent on the densities of materials. Young's modulus of material increases as the density of the material increases. The chemical properties, chain length, and connectivity of material take effects on the Young's modulus of material. Given the same densities of material the smaller number of cavities per unit volume the material has, the lower Young's modulus it shows. Based on the results, the method of predict mechanical properties of materials by the conjunction of basic experimental measurements and atomistic simulation will be discussed.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3467
Author(s):  
Anna Nocivin ◽  
Doina Raducanu ◽  
Bogdan Vasile ◽  
Corneliu Trisca-Rusu ◽  
Elisabeta Mirela Cojocaru ◽  
...  

The present paper analyzed the microstructural characteristics and the mechanical properties of a Ti–Nb–Zr–Fe–O alloy of β-Ti type obtained by combining severe plastic deformation (SPD), for which the total reduction was of etot = 90%, with two variants of super-transus solution treatment (ST). The objective was to obtain a low Young’s modulus with sufficient high strength in purpose to use the alloy as a biomaterial for orthopedic implants. The microstructure analysis was conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) investigations. The analyzed mechanical properties reveal promising values for yield strength (YS) and ultimate tensile strength (UTS) of about 770 and 1100 MPa, respectively, with a low value of Young’s modulus of about 48–49 GPa. The conclusion is that satisfactory mechanical properties for this type of alloy can be obtained if considering a proper combination of SPD + ST parameters and a suitable content of β-stabilizing alloying elements, especially the Zr/Nb ratio.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Qing-Sheng Yang ◽  
Bing-Qi Li ◽  
Xiao-Qiao He ◽  
Yiu-Wing Mai

This investigation focuses on the design of functionalization configuration at the atomic level to determine the influence of atomic structure on the mechanical properties of functionalized carbon nanotubes (F-CNTs) and their composites. Tension and compressive buckling behaviors of different configurations of CNTs functionalized by H atoms are studied by a molecular dynamics (MD) method. It is shown that H-atom functionalization reduces Young’s modulus of CNTs, but Young’s modulus is not sensitive to the functionalization configuration. The configuration does, however, affect the tensile strength and critical buckling stress of CNTs. Further, the stress-strain relations of composites reinforced by nonfunctionalized and various functionalized CNTs are analyzed.


2011 ◽  
Vol 403-408 ◽  
pp. 1173-1177
Author(s):  
Jamal Davoodi ◽  
Mohammad Javad Moradi

The aim of this research was to calculate Yong modulus, Bulk modulus and the elastic constants of Rh-20at%Pd (atom percent) nanowire. The molecular dynamics simulation technique was used to calculate the mechanical properties at constant temperature, constant pressure ensemble. The cohesive energy of the model nanowire systems was calculated by Quantum Sutton-Chen many body potential. The temperature and the pressure of the system were controlled by Nose-Hoover thermostat and Berendsen barostat, respectivly. In addition effects of the diameter of nanowire on the mechanical properties were studied. The obtained results show that, when the diameter of Rh-Pd nanowire increase, elastic constants, bulk modulus and Young modulus all increase, and when the diameter reaches about 5.5 nm, the properties began to level off and remain constant.


RSC Advances ◽  
2012 ◽  
Vol 2 (24) ◽  
pp. 9124 ◽  
Author(s):  
Nuannuan Jing ◽  
Qingzhong Xue ◽  
Cuicui Ling ◽  
Meixia Shan ◽  
Teng Zhang ◽  
...  

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