Influence of oriented topological defects on the mechanical properties of carbon nanotube heterojunctions

2013 ◽  
Vol 114 (14) ◽  
pp. 144306 ◽  
Author(s):  
Wen-Jay Lee ◽  
Jee-Gong Chang ◽  
An-Cheng Yang ◽  
Yeng-Tseng Wang ◽  
Wan-Sheng Su ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Topological Defects

Prediction of Mechanical Properties of Coiled Carbon Nanotubes by Molecular Structural Mechanics Based Finite Element Modelling

2017 ◽  
Vol 380 ◽  
pp. 124-134
Author(s):  
Hamza Azzaz ◽  
Djaffar Dahmoun ◽  
O. Chaterbache ◽  
Mohammed Azzaz
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Carbon Nanotube ◽  
Solid Mechanics ◽  
Structural Parameters ◽  
Topological Defects ◽  
Structural Mechanics ◽  
Structural Defects ◽  
One Dimensional

Carbon nanotubes (NTC) have very spectacular mechanical properties related to their nanometric structure, their perfect arrangement and their one-dimensional geometry. As with all materials, structural defects are inevitable and affects NTC properties. Among these defects, we distinguish the topological defects, the dislocations and the penta-hepta defect. But the presence of these defects is not totally harmful, because the existence of some structure like the coiled nanotube is the result of these defects. For this, in the first part of this work, the coiled carbon nanotube structure is studied, a method for the designing of this structure is proposed, the geometric parameters are detailed and the structural coefficients are determined. Therefore, a procedure for moving from a graphene sheet to a coiled nanotube is developed. Then, the second part of this study represents an attempt to calculate the spring constants of the spiral carbon nanotube. Mechanical properties of this material are investigated by means of molecular structural mechanics (MSM) method in ANSYS finite element code. The model serves as a link between the computational chemistry and the solid mechanics by substituting discrete molecular structures, with an equivalent-structural model. A coiled carbon nanotube has been modeled on the nanoscale by one-dimensional elements (3D beam). The results show a considerable influence of structural parameters (diameter, chirality, pitch and defect position) on the coiled nanotube mechanical properties.

Predictive Carbon Nanotube Models Using the Eigenvector Dimension Reduction (EDR) Method

2007 ◽  
Author(s):  
Zhimin Xi ◽  
Byeng D. Youn
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Dimension Reduction ◽  
Topological Defects ◽  
Material Design ◽  
Failure Stress ◽  
Vacancy Defects ◽  
Eigenvector Dimension Reduction ◽  
Parametric Studies ◽  
Nanotube Defects

It has been reported that a carbon nanotube (CNT) is one of the strongest materials with their high failure stress and strain. Moreover, the nanotube has many favorable features, such as high toughness, great flexibility, low density, and so on. This discovery has opened new opportunities in various engineering applications, for example, a nanocomposite material design. However, recent studies have found a substantial discrepancy between computational and experimental material property predictions, in part due to defects in the fabricated nanotubes. It is found that the nanotubes are highly defective in many different formations (e.g., vacancy, dislocation, chemical, and topological defects). Recent parametric studies with vacancy defects have found that the vacancy defects substantially affect mechanical properties of the nanotubes. Given random existence of the nanotube defects, the material properties of the nanotubes can be better understood through statistical modeling of the defects. This paper presents predictive CNT models, which enable to estimate mechanical properties of the CNTs and the nanocomposites under various sources of uncertainties. As the first step, the density and location of vacancy defects will be randomly modeled to predict mechanical properties. It has been reported that the Eigenvector Dimension Reduction (EDR) method performs probability analysis efficiently and accurately. In this paper, Molecular Dynamics (MD) simulation with a modified Morse potential model is integrated with the EDR method to predict the mechanical properties of the CNTs. To demonstrate the feasibility of the predicted model, probabilistic behavior of mechanical properties (e.g., failure stress, failure strain, and toughness) is compared with the precedent experiment results.

Li Uptake in Carbon Nanotube Systems: A First Principles Investigation

2001 ◽  
Vol 706 ◽  
Author(s):  
Vincent Meunier ◽  
Jeremy Kephart ◽  
Christopher Roland ◽  
Jerry Bernholc
Keyword(s):  
Carbon Nanotube ◽  
Ab Initio ◽  
Ball Milling ◽  
First Principles ◽  
Topological Defects ◽  
Ion Bombardment ◽  
Ion Uptake ◽  
Li Ion ◽  
Pass Through ◽  
Non Equilibrium

AbstractCarbon nanotube systems can substantially increase their capacity for Li ion uptake, provided that the nanotube interiors become accessible to the ions. We examine theoretically, with ab initio simulations, the ability of Li ions to enter a nanotube interior. While our calculations show that it is quite unlikely for the ions to pass through pristine nanotubes, they are much more likely to enter via large-sized topological defects consisting of at least 9- or more membered rings. It is unlikely that such defects are formed spontaneously, but it may be possible to induce such topological defects by violent non-equilibrium means such as ball milling, chemical means and/or ion bombardment. Indeed, recent experiments on ball milled nanotube samples do report an important increase in the Li ion uptake.

Influence of oxidation and distribution of carbon nanotube on mechanical properties of buckypaper/epoxy composites

2012 ◽  
Vol 32 (4) ◽  
pp. 248-257 ◽  
Author(s):  
Jing Guo ◽  
Min Li ◽  
Qianli Liu ◽  
Yizhuo Gu ◽  
Yanxia Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Epoxy Composites
Sign in / Sign up

Export Citation Format

Share Document