Using molecular dynamics simulations and finite element method to study the mechanical properties of nanotube reinforced polyethylene and polyketone

2015 ◽  
Vol 29 (26) ◽  
pp. 1550155 ◽  
Author(s):  
S. Rouhi ◽  
Y. Alizadeh ◽  
R. Ansari ◽  
M. Aryayi
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Finite Element ◽  
Molecular Dynamics Simulations ◽  
Polymer Matrix ◽  
Element Model ◽  
Important Change ◽  
Polymer Matrices ◽  
Transverse Tensile ◽  
Dynamics Simulations

Molecular dynamics simulations are used to study the mechanical behavior of single-walled carbon nanotube reinforced composites. Polyethylene and polyketone are selected as the polymer matrices. The effects of nanotube atomic structure and diameter on the mechanical properties of polymer matrix nanocomposites are investigated. It is shown that although adding nanotube to the polymer matrix raises the longitudinal elastic modulus significantly, the transverse tensile and shear moduli do not experience important change. As the previous finite element models could not be used for polymer matrices with the atom types other than carbon, molecular dynamics simulations are used to propose a finite element model which can be used for any polymer matrices. It is shown that this model can predict Young’s modulus with an acceptable accuracy.

Investigation of the vibration and buckling of graphynes: A molecular dynamics-based finite element model

2016 ◽  
Vol 231 (6) ◽  
pp. 1162-1178 ◽  
Author(s):  
Saeed Rouhi ◽  
Tayyeb Pour Reza ◽  
Babak Ramzani ◽  
Saeed Mehran
Keyword(s):  
Molecular Dynamics ◽  
Finite Element ◽  
Aspect Ratio ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Molecular Dynamics Simulations ◽  
Element Model ◽  
Side Length ◽  
Aspect Ratios ◽  
Dynamics Simulations

Molecular dynamics simulations are used to investigate the mechanical properties of graphynes. To study the effect of atomic structure and graphyne size on Young’s and bulk modulus, armchair and zigzag nanosheets with different side lengths and aspect ratios are considered. It is observed that at a constant aspect ratio (the ratio of height to side length), variation of side length has no significant effect on Young’s modulus of graphynes. Besides, using the obtained results by molecular dynamics simulations, a finite element model is proposed to study the vibrational and buckling behaviors of graphynes. The effects of different parameters such as nanosheet geometry and boundary conditions on the fundamental natural frequency and critical buckling force of graphynes are explored. It is shown that increasing side length has an inverse effect on the frequency and buckling force. Increasing aspect ratio results in decreasing the frequency. However, this effect reduces for longer sheets. Increasing aspect ratio results in converging the vibration curves associated with graphynes under different boundary conditions. Moreover, by increasing aspect ratio, the sensitivity of buckling force to aspect ratio variation decreases.

Vibrational analysis of single-layered silicon carbide nanosheets and single-walled silicon carbide nanotubes using nanoscale finite element method

2016 ◽  
Vol 231 (18) ◽  
pp. 3455-3461 ◽  
Author(s):  
R Ansari ◽  
S Rouhi
Keyword(s):  
Molecular Dynamics ◽  
Silicon Carbide ◽  
Finite Element ◽  
Finite Element Model ◽  
Molecular Dynamics Simulations ◽  
Three Dimensional ◽  
Vibrational Analysis ◽  
Element Model ◽  
Vibrational Behavior ◽  
Dynamics Simulations

A three-dimensional finite element model has been used here to study the vibrational behavior of silicon carbide nanosheets and nanotubes. The bonds of hexagonal lattices of SiC nanosheets have been modeled by structural beam elements, and at the corners, mass elements are placed instead of Si and C atoms. Moreover, molecular dynamics simulations are performed to verify the finite element model. Comparing the results of finite element model and molecular dynamics simulations, it is concluded that the utilized approach can predict the results of molecular dynamics simulations with a reasonable accuracy. It is observed that the atomic structure does not significantly affect the vibrational behavior of nanosheets. Besides, increasing the size of nanosheet results in decreasing the effect of geometry variation. As the aspect ratio of nanotubes increases, the effects of boundary conditions and length diminish so that the frequency envelopes tend to converge.

A Multiscale Approach to Predict the Mechanical Properties of Copper Nanofoams

MRS Advances ◽  
2019 ◽  
Vol 4 (5-6) ◽  
pp. 293-298
Author(s):  
Hang Ke ◽  
Andres Garcia Jimenez ◽  
Ioannis Mastorakos
Keyword(s):  
Molecular Dynamics ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Molecular Dynamics Simulations ◽  
Cell Structure ◽  
Element Model ◽  
Yield Function ◽  
Multiscale Approach ◽  
Element Analysis ◽  
Dynamics Simulations

ABSTRACTPure metallic nanofoams in the form of interconnected networks have shown strong potentials over the past few years in areas such as catalysts, batteries and plasmonics. However, they are often fragile and difficult to integrate in engineering applications. In order to better understand their deformation mechanisms, a multiscale approach is required to simulate the mechanical behavior of the nanofoams, although these materials will operate at the macroscale, they will still be maintaining an atomistic ordering. Hence, in this work we combine molecular dynamics (MD) and finite element analysis (FEA) to study the mechanical behavior of copper (Cu) nanofoams. Molecular dynamics simulations were performed to study the yield surface of a representative cell structure. The nanofoam structure has been generated by spinodal decomposition of binary alloy using an atomistic approach. Then, the information obtained from the molecular dynamics simulations in the form of yield function is transferred to the finite element model to study the macroscopic behavior of the Cu nanofoams. The simulated mechanical behavior of Cu nanofoams is in good agreement of the real experiment results.

scholarly journals Molecular dynamics simulations of mechanical failure in polymorphic arrangements of amyloid fibrils containing structural defects

2013 ◽  
Vol 4 ◽  
pp. 429-440 ◽  
Author(s):  
Hlengisizwe Ndlovu ◽  
Alison E Ashcroft ◽  
Sheena E Radford ◽  
Sarah A Harris
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Amyloid Fibrils ◽  
Amyloid Fibril ◽  
Steered Molecular Dynamics ◽  
Mechanical Failure ◽  
Structural Defects ◽  
Dynamics Simulations

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.

scholarly journals Atomistic investigation into the mechanical behaviour of crystalline and amorphous TiO2 nanotubes

RSC Advances ◽  
2016 ◽  
Vol 6 (33) ◽  
pp. 28121-28129 ◽  
Author(s):  
Yanan Xu ◽  
Mingchao Wang ◽  
Ning Hu ◽  
John Bell ◽  
Cheng Yan
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Titanium Dioxide ◽  
Molecular Dynamics Simulations ◽  
Mechanical Behaviour ◽  
Tio2 Nanotubes ◽  
Amorphous Tio2 ◽  
Dynamics Simulations

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

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