The Prediction of Mechanical Properties of Graphene by Molecular Mechanics and Structural Mechanics Method

2012 ◽  
Vol 583 ◽  
pp. 403-407 ◽  
Author(s):  
Yuan Zheng Cheng ◽  
Guang Yu Shi
Keyword(s):  
Mechanical Properties ◽  
Molecular Mechanics ◽  
Poisson Ratio ◽  
Structural Mechanics ◽  
Monolayer Graphene ◽  
Mechanical Parameters ◽  
Structural Members ◽  
Basic Cell ◽  
Mechanics Model ◽  
Prediction Of Mechanical Properties

Based on a new molecular structural mechanics model, the effective in-plane mechanical properties of monolayer graphene sheet is analytically analyzed in this paper. The energy equivalence between the basic cell of the atomic structure of graphene and the corresponding basic cell, defined in the homogenization of periodic cellular media, of its equivalent periodic framed structure is used to determine the mechanical properties of the equivalent structural members representing the C-C bonds of graphene. The resulting relationship between the mechanical parameters of the equivalent structural members and the force constants defined in molecular mechanics are different from those used in other molecular structural mechanics models. And these mechanical parameters yield more accurate effective mechanical properties of graphene, especially the Poisson ratio, than the existing molecular structural mechanics models.

Equivalent Mechanical Properties of Graphene Predicted by an Improved Molecular Structural Mechanics Model

2014 ◽  
Vol 609-610 ◽  
pp. 351-356
Author(s):  
Yuan Zheng Cheng ◽  
Guang Yu Shi
Keyword(s):  
Mechanical Properties ◽  
Molecular Mechanics ◽  
Poisson Ratio ◽  
Structural Mechanics ◽  
Monolayer Graphene ◽  
Graphene Sheets ◽  
Bending Rigidity ◽  
Frame Model ◽  
Mechanics Model ◽  
Energy Equivalence

Based on molecular mechanics and the stick-spiral model, this paper first presents the analytical analysis of the effective in-plane mechanical properties of both zigzag and armchair monolayer graphene sheets. We find that the equivalent in-plane elastic constants of monolayer graphene sheets are the same in the two principal directions of graphene. The effective in-plane mechanical properties of graphene are then evaluated numerically using an improved molecular structural mechanics (MSM) model, in which the flexible connections are used to characterize the bond angle variations of graphene. Furthermore, the effective bending rigidity of the beam representing a C-C bond in this improved MSM model is determined from the energy equivalence over the basic cell of graphene and the force constants given by molecular mechanics. A rigidly connected frame model with the bending stiffness of the equivalent beams for C-C bonds different from the existing structural mechanics model is also used to evaluate the mechanical properties of graphene. The flexibly connected frame model gives very good results of Youngs modulus and Poisson ratio of monolayer graphene sheet. The new rigidly connected frame model presented here also gives improved results than the existing rigidly connected frame model of graphene.

An Analytical Molecular Mechanics Model for Elastic Properties of Graphyne-n

2015 ◽  
Vol 82 (9) ◽  
Author(s):  
Juan Hou ◽  
Zhengnan Yin ◽  
Yingyan Zhang ◽  
Tienchong Chang
Keyword(s):  
Mechanical Properties ◽  
Molecular Mechanics ◽  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Building Materials ◽  
Scaling Law ◽  
Poisson's Ratio ◽  
Atomic Structures ◽  
Mechanics Model ◽  
Molecular Mechanics Model

Graphynes, a new family of carbon allotropes, exhibit superior mechanical properties depending on their atomic structures and have been proposed as a promising building materials for nanodevices. Accurate modeling and clearer understanding of their mechanical properties are essential to the future applications of graphynes. In this paper, an analytical molecular mechanics model is proposed for relating the elastic properties of graphynes to their atomic structures directly. The closed-form expressions for the in-plane stiffness and Poisson's ratio of graphyne-n are obtained for small strains. It is shown that the in-plane stiffness is a decreasing function whereas Poisson's ratio is an increasing function of the number of acetylenic linkages between two adjacent hexagons in graphyne-n. The present analytical results enable direct linkages between mechanical properties and lattice structures of graphynes; thereby, providing useful guidelines in designing graphyne configurations to suit their potential applications. Based on an effective bond density analysis, a scaling law is also established for the in-plane stiffness of graphyne-n which may have implications for their other mechanical properties.

Geometric analysis of the properties of germanene using Lifson–Wershel potential function

2020 ◽  
Vol 17 (02) ◽  
pp. 2050031
Author(s):  
Mohsen Motamedi ◽  
Ayesha Sohail
Keyword(s):  
Molecular Dynamics ◽  
Molecular Mechanics ◽  
Potential Function ◽  
Geometric Analysis ◽  
Strain Curve ◽  
Structural Mechanics ◽  
Two Dimensional ◽  
Mechanics Model ◽  
Mechanical And Electrical Properties ◽  
Step Procedure

Numerous experiments on graphene, which is a 2D carbon material with excellent mechanical and electrical properties, have been carried out in recent years. By recognizing the properties of graphene, the researchers focused on other two-dimensional materials. Several studies have been done on graphene, but other two-dimensional structures have not yet been studied extensively. In this work, Germanene’s simulation of molecular dynamics was performed and Germanene’s stress–strain curve was obtained. The mechanical properties of Germanene have been investigated by practicing the proposed method of structural molecular mechanics. The two-step procedure was followed, where, in first step with the aid of the relations governing the force field and the Lifson–Wershel potential function and structural mechanics relations, the coefficients for the BEAM elements were found, and a structural mechanics model for Germanene was proposed. Then, a germanene sheet with [Formula: see text] Ȧ was modeled and Young’s modulus of Germanene was obtained by molecular dynamics and proposed molecular mechanics methods.

scholarly journals The Young's moduli of three types of carbon allotropes: a molecular mechanics model and a finite-element method

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150628 ◽  
Author(s):  
Bo Zou ◽  
Jianxiang Shen ◽  
Peishi Yu ◽  
Junhua Zhao
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Molecular Mechanics ◽  
Explicit Solutions ◽  
Carbon Allotropes ◽  
Young’S Moduli ◽  
Mechanics Model ◽  
Finite Element Calculations ◽  
Molecular Mechanics Model ◽  
Close Form

The close-form expressions of the Young's moduli and the fracture stresses of cyclicgraphene, graphyne and supergraphene along their armchair and zigzag directions are derived based on a molecular mechanics model. Checking against present finite-element calculations of their Young's moduli shows that the explicit solutions are reasonable. The obtained analytical solutions should be of great help for understanding the mechanical properties of the graphene-like materials.

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