Mechanics of Carbon Nanotubes: A Continuum Theory Based on Interatomic Potentials

2007 ◽  
Vol 340-341 ◽  
pp. 11-20 ◽  
Author(s):  
Han Qing Jiang ◽  
Keh Chih Hwang ◽  
Young Huang
Keyword(s):  
Carbon Nanotubes ◽  
Interatomic Potential ◽  
Coefficient Of Thermal Expansion ◽  
Constitutive Models ◽  
Continuum Theory ◽  
Mechanical Deformation ◽  
Deformation Energy ◽  
Interatomic Potentials ◽  
Linear Elastic ◽  
Defect Nucleation

It is commonly believed that continuum mechanics theories may not be applied at the nanoscale due to the discrete nature of atoms. We developed a nanoscale continuum theory based on interatomic potentials for nanostructured materials. The interatomic potential is directly incorporated into the continuum theory through the constitutive models. The nanoscale continuum theory is then applied to study the mechanical deformation and thermal properties of carbon nanotubes, including (1) pre-deformation energy; (2) linear elastic modulus; (3) fracture nucleation; (4) defect nucleation; (5) electrical property change due to mechanical deformation; (6) specific heat; and (7) coefficient of thermal expansion. The nanoscale continuum theory agrees very well with the experiments and atomistic simulations without any parameter fitting, and therefore has the potential to be utilized to complex nanoscale material systems (e.g., nanocomposites) and devices (e.g., nanoelectronics).

A Finite-Temperature Continuum Theory Based on Interatomic Potentials

2005 ◽  
Vol 127 (4) ◽  
pp. 408-416 ◽  
Author(s):  
H. Jiang ◽  
Y. Huang ◽  
K. C. Hwang
Keyword(s):  
Temperature Dependence ◽  
Finite Temperature ◽  
Interatomic Potential ◽  
Coefficient Of Thermal Expansion ◽  
Harmonic Approximation ◽  
Continuum Theory ◽  
Single Wall Carbon Nanotubes ◽  
Interatomic Potentials ◽  
Atomistic Models ◽  
Continuum Theories

There are significant efforts to develop continuum theories based on atomistic models. These atomistic-based continuum theories are limited to zero temperature (T=0K). We have developed a finite-temperature continuum theory based on interatomic potentials. The effect of finite temperature is accounted for via the local harmonic approximation, which relates the entropy to the vibration frequencies of the system, and the latter are determined from the interatomic potential. The focus of this theory is to establish the continuum constitutive model in terms of the interatomic potential and temperature. We have studied the temperature dependence of specific heat and coefficient of thermal expansion of graphene and diamond, and have found good agreements with the experimental data without any parameter fitting. We have also studied the temperature dependence of Young’s modulus and bifurcation strain of single-wall carbon nanotubes.

Fracture Nucleation in Single-Wall Carbon Nanotubes Under Tension: A Continuum Analysis Incorporating Interatomic Potentials

2002 ◽  
Vol 69 (4) ◽  
pp. 454-458 ◽  
Author(s):  
P. Zhang ◽  
Y. Huang ◽  
H. Gao ◽  
K. C. Hwang
Keyword(s):  
Carbon Nanotubes ◽  
Continuum Theory ◽  
Single Wall Carbon Nanotubes ◽  
Great Promise ◽  
Interatomic Potentials ◽  
Bifurcation Instability ◽  
Continuum Analysis ◽  
Set Up ◽  
Walled Carbon Nanotubes ◽  
Fracture Nucleation

Carbon nanotubes show great promise for applications ranging from nanocomposites, nanoelectronic components, nanosensors, to nanoscale mechanical probes. These materials exhibit very attractive mechanical properties with extraordinarily high stiffness and strength, and are of great interest to researchers from both atomistic and continuum points of view. In this paper, we intend to develop a continuum theory of fracture nucleation in single-walled carbon nanotubes by incorporating interatomic potentials between carbon atoms into a continuum constitutive model for the nanotube wall. In this theory, the fracture nucleation is viewed as a bifurcation instability of a homogeneously deformed nanotube at a critical strain. An eigenvalue problem is set up to determine the onset of fracture, with results in good agreement with those from atomistic studies.

Studies of Energy and Mechanical Properties of Single-Walled Carbon Nanotubes via Higher Order Cauchy Born Rule

2007 ◽  
Vol 121-123 ◽  
pp. 1029-1032
Author(s):  
J.B. Wang ◽  
X. Guo ◽  
Hong Wu Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Continuum Theory ◽  
Single Walled Carbon Nanotubes ◽  
Higher Order ◽  
Interatomic Potentials ◽  
Born Rule ◽  
Graphite Sheet ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
Brenner Potential

Based on the higher order Cauchy-Born rule, a nanoscale finite deformation continuum theory, which links interatomic potentials and atomic microstructure of carbon nanotubes to a constitutive model, is presented for analysis of the mechanics of carbon nanotubes. By using of Tersoff-Brenner potential with two sets of parameters, the energy and Young’s modulus of graphite sheet and single-walled carbon nanotubes are studied based on the theory presented. The findings are in good agreement with the existing experimental and theoretical results.

scholarly journals Reinforcing Effect of Carbon Nanotubes/Surfactant Dispersions in Portland Cement Pastes

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Oscar A. Mendoza Reales ◽  
Caterin Ocampo ◽  
Yhan Paul Arias Jaramillo ◽  
Juan Carlos Ochoa Botero ◽  
Jorge Hernán Quintero ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Cement Matrix ◽  
Multiwalled Carbon ◽  
Element Analysis ◽  
Cement Pastes ◽  
Reinforcing Effect ◽  
Linear Elastic ◽  
Crack Propagation Process ◽  
Negative Effect ◽  
The Individual

Decoupling the individual effects of multiwalled carbon nanotubes (MWCNTs) and surfactants when used as reinforcement materials in cement-based composites is aimed in this study. Powder MWCNTs were dispersed in deionized water using different types of surfactants as chemical dispersing agents and an ultrasonic tip processor. Cement pastes with carbon nanotubes additions of 0.15% by mass of cement were produced in two steps: first, the MWCNT/surfactant dispersions were combined with the mixing water, and then, cement was added and mixed until a homogeneous paste was obtained. Mechanical properties of the pastes cured at 7 days were measured, and their fracture behavior was characterized using the linear elastic finite element analysis. It was found that the reinforcing effect of MWCNT was masked by the negative effect of surfactants in the cement matrix; nevertheless, nanotubes were capable of increasing both stress and strain capacity of the composite by controlling the crack propagation process at the tip of the crack.

Scanning Thermal Microscopy of Carbon Nanotubes

2000 ◽  
Author(s):  
Li Shi ◽  
Sergei Plyasunov ◽  
Adrian Bachtold ◽  
Paul L. McEuen ◽  
Arunava Majumdar
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Imaging ◽  
Heat Dissipation ◽  
Energy Transport ◽  
Imaging Technique ◽  
Mechanical Deformation ◽  
Phonon Transport ◽  
Scanning Thermal Microscopy ◽  
Thermal Microscopy ◽  
Nanoelectronic Circuits

Abstract This paper reports the use of scanning thermal microscopy (SThM) for studying heat dissipation and phonon transport in nanoelectronic circuits consisting of carbon nanotubes (CNs). Thermally designed and batch fabricated SThM probes were used to resolve the phonon temperature distribution in the CN circuits with a spatial resolution of 50 nm. Heat dissipation at poor metal-CN contacts could be readily found by the thermal imaging technique. Important questions regarding energy transport in nanoelectronic circuits, such as where is heat dissipated, whether the electrons and phonons are in equilibrium, how phonons are transported, and what are the effects of mechanical deformation on the transport and dissipation properties, are addressed in this work.

scholarly journals Finite element modelling of an energy-geomembrane underground pumped hydroelectric energy storage system

2020 ◽  
Vol 205 ◽  
pp. 07001
Author(s):  
Hans Henning Stutz ◽  
Peter Norlyk ◽  
Kenneth Sørensen ◽  
Lars Vabbersgaard Andersen ◽  
Kenny Kataoka Sørensen ◽  
...  
Keyword(s):  
Finite Element ◽  
Energy Storage ◽  
Storage System ◽  
Constitutive Models ◽  
Energy System ◽  
Energy Storage System ◽  
Elastic Model ◽  
Hydroelectric Energy ◽  
Linear Elastic ◽  
Soil Behaviour

The increasing need for energy storage technology has led to a massive interest in novel energy storage methods. The energy geomembrane system is such a novel energy storage method. The concept of the system is briefly introduced, and a holistic numerical model of the system is presented. The model uses advanced finite-element techniques to model the energy storage system using fluid cavity elements. The developed geomembrane energy system is modelled with different constitutive models to represent the soil behaviour: a linear elastic model, a nonlinear Mohr-Coulomb model, and a hypoplastic constitutive model. The consequences of these different models on the results are studied. Hereby, the focus is the first inflation and deflation cycle of the system.

scholarly journals Coefficient of thermal expansion of carbon nanotubes measured by Raman spectroscopy

2014 ◽  
Vol 104 (5) ◽  
pp. 051907 ◽  
Author(s):  
Libo Deng ◽  
Robert J. Young ◽  
Ian A. Kinloch ◽  
Rong Sun ◽  
Guoping Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion
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