Molecular mechanics-based finite element analysis of graphene sheet and carbon nanotubes using the rebo potential

2017 ◽  
Vol 08 (03) ◽  
pp. 1750038 ◽  
Author(s):  
Konstantinos Tserpes ◽  
Antonis Koumpias
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element ◽  
Molecular Mechanics ◽  
Graphene Sheet ◽  
Carbon Nanostructures ◽  
Element Analysis ◽  
Angle Variation ◽  
Fracture Patterns ◽  
Rebo Potential ◽  
Dynamics Simulations

Molecular mechanics-based finite element (FE) models of graphene sheet and single-walled zigzag and armchair carbon nanotubes (CNTs) are developed on the basis of the assumption that the carbon nanostructures, when loaded, behave like frame structures. The behavior of carbon–carbon bonds, which are represented by beam elements, is simulated using the many-body second generation reactive empirical bond order (REBO) potential. By means of the FE models, the tensile behavior of carbon nanostructures is simulated. The FE models are verified against molecular dynamics simulations. The computed results in terms of tensile stress–strain curves and fracture patterns are compared with results obtained using the pairwise modified-Morse potential. Different tensile properties and fracture patterns are predicted using the two potentials. This is mainly attributed to the deviations in the force–bond length curves and to the contribution of bond angle variation which is present in REBO. The present work is the first attempt to implement the REBO potential into a continuum model of carbon nanostructures and paves the way for a more systematic incorporation of atomistic simulation methods into continuum models.

Molecular Mechanics Based Finite Element for Carbon Nanotube Modeling

2006 ◽  
Author(s):  
Theodosios C. Theodosiou ◽  
Dimitris A. Saravanos
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Carbon Nanotube ◽  
Molecular Mechanics ◽  
Potential Model ◽  
Element Analysis ◽  
Molecular Potential ◽  
Theoretical Predictions ◽  
Semi Empirical

In this paper a new method is introduced for carbon nanotubes modeling. It combines features of Molecular Mechanics and Finite Element Analysis. This method is based on the development of a new finite element, whose internal energy is determined by the semi-empirical Brenner molecular potential model; all quantities are calculated analytically in order to gain more accuracy. The method is validated through comparisons to results provided by other researchers and are obtained either by experimental procedures or theoretical predictions. The bending and shearing of CNTs is also simulated.

Multiscale Modeling and Mechanical Properties of Zigzag CNT and Triple-Layer Graphene Sheet Based on Atomic Finite Element Method

2015 ◽  
Vol 33 ◽  
pp. 92-105 ◽  
Author(s):  
Jia Fu ◽  
Fabrice Bernard ◽  
Siham Kamali-Bernard
Keyword(s):  
Finite Element Method ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Graphene Sheet ◽  
Atomic Scale ◽  
Single Layer Graphene ◽  
Element Analysis ◽  
Layer Graphene ◽  
Triple Layer ◽  
Element Method

An Atomic Finite Element Analysis is developed in this paper. At atomic scale, the interatomic bonding forces of Van der Waals and the covalent chemical bond are taken into account. The methodology is applied to study the behavior of carbon nanotubes, whose development has experienced strong growth in recent years and that can be used for quality mechanical reinforcement. These carbon nanotubes are formed by repeating zigzag carbon-carbon bonds. Development of atomic finite element method (AFEM) methodology can be traced back to the homogenized elastic properties of various graphene structures (single-layer graphene sheet, Zig-zag single-walled carbon nanotubes, triple-layer graphene sheet).

Analytical and Numerical Predictions of Thermoelastic Properties of Carbon Single-Walled Nanotubes

Aerospace ◽  
2005 ◽  
Author(s):  
Vinod P. Veedu ◽  
Davood Askari ◽  
Mehrdad N. Ghasemi-Nejhad
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Graphene Sheet ◽  
Effective Properties ◽  
Constitutive Models ◽  
Thermoelastic Properties ◽  
Asymptotic Homogenization ◽  
Element Analysis ◽  
Single Walled Nanotubes ◽  
Numerical Predictions

The objective of this paper is to develop constitutive models to predict thermoelastic properties of carbon single-walled nanotubes using analytical, asymptotic homogenization, and numerical, finite element analysis, methods. In our approach, the graphene sheet is considered as a non-homogeneous network shell layer which has zero material properties in the regions of perforation and whose effective properties are estimated from the solution of the appropriate local problems set on the unit cell of the layer. Our goal is to derive working formulas for the entire complex of the thermoelastic properties of the periodic network. The effective thermoelastic properties of carbon nanotubes were predicted using asymptotic homogenization method. Moreover, in order to verify the results of analytical predictions, a detailed finite element analysis is followed to investigate the thermoelastic response of the unit cells and the entire graphene sheet network.

scholarly journals Mechanical Properties of Pentagraphene-based Nanotubes: A Molecular Dynamics Study

MRS Advances ◽  
2018 ◽  
Vol 3 (1-2) ◽  
pp. 97-102 ◽  
Author(s):  
J. M. de Sousa ◽  
A. L. Aguiar ◽  
E. C. Girão ◽  
Alexandre F. Fonseca ◽  
A. G. Souza Filho ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Elastic Behavior ◽  
Fracture Patterns ◽  
Nanostructured Systems ◽  
Reaxff Force Field ◽  
Dynamics Simulations ◽  
Different Diameters ◽  
Graphene Membranes

ABSTRACTThe study of the mechanical properties of nanostructured systems has gained importance in theoretical and experimental research in recent years. Carbon nanotubes (CNTs) are one of the strongest nanomaterials found in nature, with Young’s Modulus (EY) in the order 1.25 TPa. One interesting question is about the possibility of generating new nanostructures with 1D symmetry and with similar and/or superior CNT properties. In this work, we present a study on the dynamical, structural, mechanical properties, fracture patterns and EY values for one class of these structures, the so-called pentagraphene nanotubes (PGNTs). These tubes are formed rolling up pentagraphene membranes (which are quasi-bidimensional structures formed by densely compacted pentagons of carbon atoms in sp3 and sp2 hybridized states) in the same form that CNTs are formed from rolling up graphene membranes. We carried out fully atomistic molecular dynamics simulations using the ReaxFF force field. We have considered zigzag-like and armchair-like PGNTs of different diameters. Our results show that PGNTs present EY ∼ 800 GPa with distinct elastic behavior in relation to CNTs, mainly associated with mechanical failure, chirality dependent fracture patterns and extensive structural reconstructions.

scholarly journals Vibrational Characteristics of Zigzag, Armchair and Chiral Cantilever Single-Walled Carbon Nanotubes

2013 ◽  
Vol 22 (6) ◽  
pp. 096369351302200
Author(s):  
S.K. Jalan ◽  
B. Nageswara Rao ◽  
S. Gopalakrishnan
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Single Walled Carbon Nanotubes ◽  
Finite Element Models ◽  
Element Analysis ◽  
Single Walled Carbon ◽  
Empirical Relations ◽  
Vibrational Characteristics ◽  
Walled Carbon Nanotubes

Finite element analysis has been performed to study vibrational characteristics of cantilever single walled carbon nanotubes. Finite element models are generated by specifying the C-C bond rigidities, which are estimated by equating energies from molecular mechanics and continuum mechanics. Bending, torsion, and axial modes are identified based on effective mass for armchair, zigzag and chiral cantilever single walled carbon nanotubes, whose Young's modulus is evaluated from the bending frequency. Empirical relations are provided for frequencies of bending, torsion, and axial modes.

scholarly journals Dynamic instability of a compound nanocomposite shell

2021 ◽  
Vol 27 (5) ◽  
pp. 60-70
Author(s):  
N.H. Sakhno ◽  
◽  
K.V. Avramov ◽  
B.V. Uspensky ◽  
◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Cylindrical Shell ◽  
Supersonic Flow ◽  
Uniform Distribution ◽  
Critical Pressure ◽  
Natural Frequencies ◽  
Dynamic Instability ◽  
Element Analysis

Free oscillations and dynamic instability due to supersonic airflow pressure are investigated in a functional-gradient compound composite conical-cylindrical shell made of a carbon nanotubes-reinforced material. Nanocomposite materials with a linear distribution of the volumetric fraction of nanotubes over the thickness are considered. Extended mixture rule is used to estimate nanocomposite’s mechanical characteristics. A high-order shear deformation theory is used to represent the shell deformation. The assumed-mode technique, along with a Rayleigh-Ritz method, is applied to obtain the equations of the structure motion. To analyze the compound structure dynamics, a new system of piecewise basic functions is suggested. The pressure of a supersonic flow on the shell is obtained by using the piston theory. An example of the dynamic analysis of a nanocomposite conical-cylindrical shell in the supersonic gas flow is considered. The results of its modal analysis using the Rayleigh-Ritz technique are close to the natural frequencies of the shell obtained by finite element analysis. In this case, finite element analysis can only be used for shells made of material with a uniform distribution of nanotubes over the thickness. The dependence of the natural frequencies of a compound shell on the ratio of the lengths of the conical and cylindrical parts is studied. The dependence of the critical pressure of a supersonic flow on the Mach numbers and the type of carbon nanotubes reinforcement is investigated. Shells with a concentration of nanotubes predominantly near the outer and inner surfaces are characterized by higher values of natural frequencies and critical pressure than the shells with a uniform distribution of nanotubes or with a predominant concentration of nanotubes inside the shell.

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