Mechanical Properties of Vacancy-containing Graphene and Graphite Estimated by Molecular Dynamics Simulations

2011 ◽  
Vol 1362 ◽  
Author(s):  
Akihiko Ito ◽  
Shingo Okamoto

ABSTRACTUsing molecular dynamics (MD) simulation, we investigated the mechanical properties of graphene and graphite, which contain cluster-type vacancies. We found that as the vacancy size increases, the tensile strength drastically decreases to at least 56% of that of pristine graphene, whereas Young’s modulus hardly changes. In vacancy-containing graphene, we also found that slip deformation followed by fracture occurs under zigzag tension. In general, tensile strength decreases as the size of cluster-type vacancies increases. However, the tensile strength of graphene with a clustered sextuple vacancy increases as the vacancy disappears because slip deformation proceeds. Furthermore, we found that slip deformation by vacancies in graphite occurs less easily than in graphene.Our results suggest that the shape of vacancies affects the strengths of graphene and graphite.

2012 ◽  
Vol 472-475 ◽  
pp. 1813-1817 ◽  
Author(s):  
Yu Lin Yang ◽  
Zhe Yong Fan ◽  
Ning Wei ◽  
Yong Ping Zheng

In this paper the mechanical properties of a series of hydrogen functionalized graphyne are investigated through acting tensile loads on the monolayer networks. Molecular dynamics simulations are performed to calculate the fracture strains and corresponding maximum forces for pristine graphyne along both armchair and zigzag directions. Furthermore, hydrogen functionalized graphynes with different functionalization sites are analyzed to investigate the effect of functionlization on the mechanical performance. Finally, Young's modulus of all the investigated architectures are computed. The obtained results show that monolayer graphyne is mechanically stable with high strength and stiffness, and the mechanical performance can be tuned through structure engineering and functionalization.


2015 ◽  
Vol 17 (48) ◽  
pp. 32425-32435 ◽  
Author(s):  
Jianyang Wu ◽  
Gaosheng Nie ◽  
Jun Xu ◽  
Jianying He ◽  
Qingchi Xu ◽  
...  

Classic molecular dynamics (MD) simulation of hypothetical MoS2NT nanorings and their woven hierarchical structures shows a strong dimension-dependent structural stability, and reveals that the hierarchical structures with 4-in-1 weaves exhibit high tensile strength and Young's modulus.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Van-Trung Pham ◽  
Te-Hua Fang

Abstract We conduct molecular dynamics simulations to study the mechanical and thermal properties of monolayer indium selenide (InSe) sheets. The influences of temperature, intrinsic structural defect on the tensile properties were assessed by tensile strength, fracture strain, and Young’s modulus. We found that the tensile strength, fracture strain, and Young’s modulus reduce as increasing temperature. The results also indicate that with the existence of defects, the stress is concentrated at the region around the vacancy leading to the easier destruction. Therefore, the mechanical properties were considerably decreased with intrinsic structural defects. Moreover, Young’s modulus is isotropy in both zigzag and armchair directions. The point defect almost has no influence on Young’s modulus but it strongly influences the ultimate strength and fracture strain. Besides, the effects of temperature, length size, vacancy defect on thermal conductivity (κ) of monolayer InSe sheets were also studied by using none-equilibrium molecular dynamics simulations. The κ significantly arises as increasing the length of InSe sheets. The κ of monolayer InSe with infinite length at 300 K in armchair direction is 46.18 W/m K, while in zigzag direction is 45.87 W/m K. The difference of κ values in both directions is very small, indicating the isotropic properties in thermal conduction of this material. The κ decrease as increasing the temperature. The κ goes down with the number of atoms vacancy defect increases.


2013 ◽  
Vol 4 ◽  
pp. 429-440 ◽  
Author(s):  
Hlengisizwe Ndlovu ◽  
Alison E Ashcroft ◽  
Sheena E Radford ◽  
Sarah A Harris

We examine how the different steric packing arrangements found in amyloid fibril polymorphs can modulate their mechanical properties using steered molecular dynamics simulations. Our calculations demonstrate that for fibrils containing structural defects, their ability to resist force in a particular direction can be dominated by both the number and molecular details of the defects that are present. The simulations thereby suggest a hierarchy of factors that govern the mechanical resilience of fibrils, and illustrate the general principles that must be considered when quantifying the mechanical properties of amyloid fibres containing defects.


Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 440 ◽  
Author(s):  
Aaron Liu ◽  
Qing Peng

Graphene is one of the most important nanomaterials. The twisted bilayer graphene shows superior electronic properties compared to graphene. Here, we demonstrate via molecular dynamics simulations that twisted bilayer graphene possesses outstanding mechanical properties. We find that the mechanical strain rate and the presence of cracks have negligible effects on the linear elastic properties, but not the nonlinear mechanical properties, including fracture toughness. The “two-peak” pattern in the stress-strain curves of the bilayer composites of defective and pristine graphene indicates a sequential failure of the two layers. Our study provides a safe-guide for the design and applications of multilayer grapheme-based nanoelectronic devices.


RSC Advances ◽  
2016 ◽  
Vol 6 (33) ◽  
pp. 28121-28129 ◽  
Author(s):  
Yanan Xu ◽  
Mingchao Wang ◽  
Ning Hu ◽  
John Bell ◽  
Cheng Yan

The mechanical properties of titanium dioxide (TiO2) nanotubes are studied based on molecular dynamics simulations.


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