Influence of Defects on Elastic Buckling Properties of Single-Layered Graphene Sheets

2014 ◽  
Vol 636 ◽  
pp. 11-14 ◽  
Author(s):  
Bao Long Li ◽  
Li Jun Zhou ◽  
Jian Gao Guo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Vacancy Defect ◽  
Elastic Buckling ◽  
Graphene Sheets ◽  
Effect Factors ◽  
Vacancy Defects ◽  
Size Dependent ◽  
Buckling Stress ◽  
Geometrical Dimensions

Molecular structural mechanics based finite element method has been applied to study the effects of two types of Stone-Wales (SW) defects and vacancy defect on elastic buckling properties of single-layered graphene sheets (SLGSs). The defect effect factors of critical buckling stresses are calculated for the defective SLGSs with different chirality and geometrical dimensions. It is proved that defect effect factors are size-dependent and chirality-dependent. The results show that the vacancy defects will always weaken the SLGSs’ stability, and two types of SW defects have different effects on zigzag and armchair SLGSs. What’s more, the positions of defects also have remarkable influence on the critical buckling stress of SLGSs.

scholarly journals Monte Carlo-Based Finite Element Method for the Study of Randomly Distributed Vacancy Defects in Graphene Sheets

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Liu Chu ◽  
Jiajia Shi ◽  
Eduardo Souza de Cursi ◽  
Xunqian Xu ◽  
Yazhou Qin ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Monte Carlo ◽  
Natural Frequencies ◽  
Vacancy Defect ◽  
Honeycomb Lattice ◽  
Graphene Sheets ◽  
Pristine Graphene ◽  
Vacancy Defects ◽  
Element Method

This paper proposed an effective stochastic finite element method for the study of randomly distributed vacancy defects in graphene sheets. The honeycomb lattice of graphene is represented by beam finite elements. The simulation results of the pristine graphene are in accordance with literatures. The randomly dispersed vacancies are propagated and performed in graphene by integrating Monte Carlo simulation (MCS) with the beam finite element model (FEM). The results present that the natural frequencies of different vibration modes decrease with the augment of the vacancy defect amount. When the vacancy defect reaches 5%, the regularity and geometrical symmetry of displacement and rotation in vibration behavior are obviously damaged. In addition, with the raise of vacancy defects, the random dispersion position of vacancy defects increases the variance in natural frequencies. The probability density distributions of natural frequencies are close to the Gaussian and Weibull distributions.

The Theoretical Investigation on Critical Buckling Stress of Graphene Nanosheets

2016 ◽  
Vol 859 ◽  
pp. 79-84
Author(s):  
Li Jun Zhou ◽  
Jian Gao Guo ◽  
Bao Long Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Graphene Nanosheets ◽  
Structural Mechanics ◽  
Elastic Buckling ◽  
Boundary Constraints ◽  
Buckling Stress ◽  
Good Consistency ◽  
Analytical Expressions ◽  
Geometrical Dimensions

The elastic buckling behaviors of graphene nanosheets are investigated via molecular structural mechanics based finite element method. The size-and chirality-dependent critical buckling stresses of monolayer and bilayer graphene nanosheets are calculated for different geometrical dimensions and boundary constraints, respectively. By analogy with classical buckling theory of elastic plate, the analytical expressions of critical buckling stress are derived for the graphene nanosheets with different boundary constraints, and the comparisons of analytical results with the counterparts obtained by molecular structural mechanics simulation show a good consistency.

scholarly journals Buckling Analysis of Vacancy-Defected Graphene Sheets by the Stochastic Finite Element Method

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1545 ◽  
Author(s):  
Liu Chu ◽  
Jiajia Shi ◽  
Shujun Ben
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Probability Density Distribution ◽  
Graphene Sheets ◽  
Stochastic Finite Element ◽  
Vacancy Defects ◽  
Buckling Behavior ◽  
Element Method ◽  
Defected Graphene

Vacancy defects are unavoidable in graphene sheets, and the random distribution of vacancy defects has a significant influence on the mechanical properties of graphene. This leads to a crucial issue in the research on nanomaterials. Previous methods, including the molecular dynamics theory and the continuous medium mechanics, have limitations in solving this problem. In this study, the Monte Carlo-based finite element method, one of the stochastic finite element methods, is proposed and simulated to analyze the buckling behavior of vacancy-defected graphene. The critical buckling stress of vacancy-defected graphene sheets deviated within a certain range. The histogram and regression graphs of the probability density distribution are also presented. Strengthening effects on the mechanical properties by vacancy defects were detected. For high-order buckling modes, the regularity and geometrical symmetry in the displacement of graphene were damaged because of a large amount of randomly dispersed vacancy defects.

Elastic buckling of rectangular fiber-metal laminated plates under uniaxial compression

2019 ◽  
Vol 33 (12) ◽  
pp. 1629-1651 ◽  
Author(s):  
George SE Bikakis ◽  
Costas D Kalfountzos ◽  
Efstathios E Theotokoglou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Aspect Ratio ◽  
Mode Shapes ◽  
Elastic Buckling ◽  
Simple Method ◽  
Buckling Stress ◽  
Buckling Coefficient ◽  
Fiber Metal ◽  
Element Method

In this article, the elastic buckling response of rectangular simply supported and clamped fiber-metal laminates (FMLs) subjected to uniaxial compressive loading is investigated using the finite element method and eigenvalue buckling analysis. Using validated finite element method (FEM) models, the buckling coefficient-aspect ratio diagrams and the mode shapes of nine GLARE grades are obtained and studied along with the diagrams and the mode shapes of three unidirectional glass-epoxy composites and monolithic 2024-T3 aluminum. It is found that the critical average buckling stress and the buckling load of the materials increases for increasing metal volume fraction, when the plate aspect ratio is greater than 1.5. The rule of mixtures is evaluated and found to be a simple method to estimate approximately the average critical buckling stress of the GLARE plates. An approximate formula is derived for the estimation of the critical buckling coefficient of the GLARE plates using the buckling coefficients of their constituents. The applicability of the results to thermoplastic-based FMLs is discussed.

A Size-Dependent Coupled Symplectic and Finite Element Method for Steady-State Forced Vibration of Built-Up Nanobeam Systems

2019 ◽  
Vol 19 (07) ◽  
pp. 1950081 ◽  
Author(s):  
Zhenhuan Zhou ◽  
Junhai Fan ◽  
C. W. Lim ◽  
Dalun Rong ◽  
Xinsheng Xu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Steady State ◽  
Forced Vibration ◽  
Numerical Solutions ◽  
New Approach ◽  
Size Dependent ◽  
Numerical Result ◽  
Proper Comparison ◽  
Element Method

A novel size-dependent coupled symplectic and finite element method (FEM) is proposed to study the steady-state forced vibration of built-up nanobeam system resting on elastic foundations. The overall system is modeled as a combination of nonlocal Timoshenko beams. A new analytical subsystem modeling with formulation and another numerical subsystem modeling are developed and discussed. In the analytical subsystem model, the uniform nanobeams are modeled and solved by a new approach based on a series of analytical symplectic eigensolutions. The numerical subsystem model applies a nonlocal FEM to solve nonuniform nanobeams. Analytical and numerical solutions are presented, and a proper comparison between the two approaches is established. Comprehensive and accurate numerical result is subsequently presented to illustrate the accuracy and reliability of the coupled method. The new results established are expected to have reference values for future studies.

Finite element investigation of the vibrational behavior of concentric multi-walled boron nitride and carbon nanotubes

2017 ◽  
Vol 31 (04) ◽  
pp. 1750018 ◽  
Author(s):  
R. Ansari ◽  
S. Rouhi ◽  
A. Nikkar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boron Nitride ◽  
Natural Frequencies ◽  
Vacancy Defect ◽  
Boron Nitride Nanotubes ◽  
The Finite Element Method ◽  
Zigzag Nanotubes ◽  
Vibrational Behavior ◽  
Vibrational Characteristics

This paper concerns the vibrational behavior of concentric double-walled and triple-walled carbon and boron nitride nanotubes using the finite element method. Armchair and zigzag nanotubes with different lengths and diameters are considered. Moreover, different boundary conditions are applied on the nanotubes. It is observed that in double-walled nanotubes, when the inner and outer layers are respectively from boron nitride and carbon, the frequencies are larger than those in the reverse arrangement. Investigating the effect of diameter on the first 10 natural frequencies of double-walled and triple-walled nanotubes showed that nanotubes with larger diameters possess smaller frequencies. The effect of diameter is more significant for higher modes. Finally, comparisons are made between the vibrational behavior of concentric carbon and boron nitride double-walled and triple-walled nanotubes. Considering the effect of vacancy defect on the vibrational characteristics of the nanotubes revealed that when all of the walls of the nanotubes are defective, the largest diminish occurs for the fundamental natural frequencies.

Constrained shell finite element method for elastic buckling analysis of thin-walled members

2019 ◽  
Vol 145 ◽  
pp. 106409 ◽  
Author(s):  
Sheng Jin ◽  
Zhanjie Li ◽  
Fang Huang ◽  
Dan Gan ◽  
Rui Cheng ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Buckling Analysis ◽  
Elastic Buckling ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Element Method
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