Equivalent Young's modulus and thickness of graphene sheets for the continuum mechanical models

2014 ◽  
Vol 104 (22) ◽  
pp. 223101 ◽  
Author(s):  
Jin-Xing Shi ◽  
Toshiaki Natsuki ◽  
Xiao-Wen Lei ◽  
Qing-Qing Ni
RSC Advances ◽  
2012 ◽  
Vol 2 (24) ◽  
pp. 9124 ◽  
Author(s):  
Nuannuan Jing ◽  
Qingzhong Xue ◽  
Cuicui Ling ◽  
Meixia Shan ◽  
Teng Zhang ◽  
...  

Author(s):  
Khalid I. Alzebdeh

The mechanical behaviour of a single-layer nanostructured graphene sheet is investigated using an atomistic-based continuum model. This is achieved by equating the stored energy in a representative unit cell for a graphene sheet at atomistic scale to the strain energy of an equivalent continuum medium under prescribed boundary conditions. Proper displacement-controlled (essential) boundary conditions which generate a uniform strain field in the unit cell model are applied to calculate one elastic modulus at a time. Three atomistic finite element models are adopted with an assumption that force interactions among carbon atoms can be modeled by either spring-like or beam elements. Thus, elastic moduli for graphene structure are determined based on the proposed modeling approach. Then, effective Young’s modulus and Poisson’s ratio are extracted from the set of calculated elastic moduli. Results of Young’s modulus obtained by employing the different atomistic models show a good agreement with the published theoretical and numerical predictions. However, Poisson’s ratio exhibits sensitivity to the considered atomistic model. This observation is supported by a significant variation in estimates as can be found in the literature. Furthermore, isotropic behaviour of in-plane graphene sheets was validated based on current modeling.


1995 ◽  
Vol 4 (3) ◽  
pp. 096369359500400
Author(s):  
G. Hernández ◽  
R. Rodríguez ◽  
A. Maciel ◽  
M.V. García-Garduño ◽  
V.M. Castaño

Mechanical testing the behaviour of polybutadiene-cellulose diacetate (functionallized) was performed. The cellulose diacetate was chemically modified to improve the interfacial bonding between the components. The results indicate that the Young's modulus is increased substantially as the content of the functionallized component is increased. Finally, a comparison to theoretical mechanical models is shown.


Holzforschung ◽  
2008 ◽  
Vol 62 (5) ◽  
Author(s):  
Xinfeng Xie ◽  
Barry Goodell ◽  
Yuhui Qian ◽  
Michael Peterson ◽  
Jody Jellison

Abstract Effects of the heating rate on the physical properties of carbonized wood were investigated by comparing the dimensional shrinkage, electrical resistivity, Young's modulus, and the evolution of turbostratic crystallites in maple hardwood samples carbonized at 600°C, 800°C, and 1000°C under heating regimes of 3°C h-1 and 60°C h-1. Important carbonized wood properties that developed at high temperature and high heating rates could also be produced at slow heating rates and lower temperatures. Furthermore, slow heating rates promoted the formation and growth of graphene sheets in turbostratic crystallites, which had a significant influence on the electrical resistivity and Young's modulus of the carbonized wood. The results indicate that the graphene sheets of turbostratic crystallites formed during wood carbonization were arranged parallel to the axial direction of wood cells and at an angle to the circumference of wood cells in the cross-sectional plane. With regard to the production of carbon products, a decrease in the heating rate may be beneficial for char properties and the prevention of crack production during manufacture of large monolithic carbon specimens from wood and wood-based materials.


2013 ◽  
Vol 290 ◽  
pp. 15-20
Author(s):  
Dong Mei Luo ◽  
Hong Yang ◽  
Qiu Yan Chen ◽  
Ying Long Zhou

In this paper, two kinds of micro-mechanical models are utilized to predict the effective Young's modulus for hybrid composites including fiber-like, spherical and needle inclusions in an isotropic matrix. The two models of Multi-Phase Mori-Tanaka Model (MP model) and Multi-Step Mori-Tanaka Model (MS model) are proposed by the authors in a series of interrelated research. The results show that the shape and the Young’s modulus of inclusion, aspect ratio of fiber-like inclusion are the controlling factors to influence the Young's modulus, and MP model is more rational to predict the effective Young’s modulus of hybrid composites reinforced with multi-shape inclusions.


2016 ◽  
Vol 51 (23) ◽  
pp. 3299-3313 ◽  
Author(s):  
Sumit Sharma ◽  
Pramod Kumar ◽  
Rakesh Chandra

Single layer graphene sheets and carbon nanotubes have resulted in the development of new materials for a variety of applications. Though there are a large number of experimental and numerical studies related to these nanofillers, still there is a lack of understanding of the effect of geometrical characteristics of these nanofillers on their mechanical properties. In this study, molecular dynamics simulation has been used to assess this issue. Two different computational models, single layer graphene sheets–copper and carbon nanotube–copper composites have been examined to study the effect of nanofiller geometry on Young’s modulus and thermal conductivity of these nanocomposites. Effect of increase in temperature on Young’s modulus has also been predicted using molecular dynamics. The effect of nanofiller volume fraction ( Vf) on Young’s modulus and thermal conductivity has also been studied. Results of thermal conductivity obtained using molecular dynamics have been compared with theoretical models. Results show that with increase in Vf the Young’s modulus as well as thermal conductivity of single layer graphene sheets–Cu composites increases at a faster rate than that for carbon nanotube–Cu composite. For the same Vf, the Young’s modulus of single layer graphene sheets–Cu composite is higher than carbon nanotube–Cu composite.


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