Dislocation re-emission induced staged work hardening in graphene-nanotwin reinforced Cu: A molecular dynamics simulation study

2022 ◽  
pp. 146442072110681
Author(s):  
YQ Hu ◽  
S Zhang ◽  
P Huang ◽  
F Wang
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Work Hardening ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Cyclic Process ◽  
Hardening Behavior ◽  
Metallic Composites ◽  
Twin Spacing ◽  
Special Arrangement

Graphene and nanotwins are two effective reinforced microstructural features to achieve improved mechanical properties of metallic composites, while the two features are generally applied separately. In this study, graphene/nano-twinned Cu nanocomposites models with different arrangement of the graphene and twin boundaries were designed by using molecular dynamics (MD) simulations, and the dislocation processes and the interactions between dislocation and graphene/twin were simulated and investigated. The simulation results indicated the arrangement of graphene and nanotwin affects the work hardening behaviors in the graphene/nano-twinned Cu composites, i.e., two staged work hardening behavior corresponded to cyclic process of dislocation hindrance-absorption-reemission in the model with relatively small twin spacing and twin-graphene spacing, while the work hardening dominated by dislocation intersection and multiplication occurred in the model with large twin-spacing. The simulation provided herein demonstrated that the special arrangement of graphene and nanotwins led a way to tailoring the mechanical properties of metallic composites with various work hardening behaviors. Graphical abstract Highlights 1. Dislocation reactions between twins and graphene were simulated and analyzed. 2. Twin-graphene distance and the twin distance play key roles in the reaction. 3. The mechanism corresponding to work hardening changes in the limited two distances.

Investigating the Effect of Stone-Wales Defect on Young Modulus of Armchair Single Wall Carbon Nanotube Using Molecular Dynamics Simulation

2010 ◽  
Author(s):  
H. Rezaei Nejad ◽  
M. Ghasemi ◽  
A. Shahabi ◽  
S. M. Mirnouri Langroudi
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Young Modulus ◽  
Effective Elastic Modulus ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Fortran Code ◽  
Wales Defect

Effect of Stone-Wales percentage defect on effective elastic modulus of single-walled carbon nanotubes (SWCNT) is investigated. The Stone-Wales defect is a crystallographic defect that happens in nanotubes and is believed to affect the nanotubes mechanical properties. In order to calculate the mechanical properties of SWCNTs under axial tension, molecular dynamics (MD) simulations using the Morse potential is performed. An in house FORTRAN code is developed and utilized. The Young’s modulus of the perfect SWCNTs and those with different defect percentage is obtained using the classical elasticity theory. It is observed that for low percentage of defect (less than 8%) as the diameter increases the Young’s modulus of SWCNTs slightly increases. However, for high percentage of defect (more than 8%) as diameter increases the Young modulus clearly decreases.

scholarly journals Molecular Dynamics Simulation Study of Eucommiaulmoides GUM/AG Nanoparticle Composites

2017 ◽  
Vol 26 (4) ◽  
pp. 096369351702600
Author(s):  
Fei-Zhou Li ◽  
Zhen-Lin Lu ◽  
Yuntao Xi ◽  
Xin-sheng Wang ◽  
Ming-qiang Zhu
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Pressure Coefficient ◽  
Amorphous State ◽  
Md Simulations ◽  
Amorphous Structure ◽  
Dynamics Simulation ◽  
Ag Nanoparticle ◽  
Ag Nps ◽  
Eucommia Ulmoides Gum

A study of eucommia ulmoides gum (EUG)/Ag nanoparticle (NP) composites by molecular dynamics (MD) simulations to understand their structure, polarizability, thermodynamic properties, and mechanical properties is proposed. The effects of simulation temperature and Ag NPs size on these parameters were also studied. The results revealed that the composites exhibited an isotropic amorphous structure, and the distribution uniformity of the Ag NPs was enhanced by changing the simulation temperature. Several atoms of the Ag NPs were in an amorphous state, and a polarized layer was observed on the interface between the Ag NPs and the eucommia ulmoide matrix. The interface size increased as the temperature increased and nanoparticles size decreased. The isochoric heat capacity and thermal pressure coefficient of the EUG/Ag-NP composites exhibited significant size effects and improved thermal interferences, which indicated that the presence of the Ag NPs had a positive effect on the mechanical properties of the EUG.

Size Dependent Mechanical Properties of Graphene Nanoribbons: Molecular Dynamics Simulation

2013 ◽  
Vol 749 ◽  
pp. 456-460 ◽  
Author(s):  
Yun Jin Sun ◽  
Fei Ma ◽  
K.W. Xu
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Mechanical Stability ◽  
Graphene Nanoribbons ◽  
Md Simulations ◽  
Strain Engineering ◽  
Dynamics Simulation ◽  
Size Dependent ◽  
Key Issues ◽  
Strain Stress

Strain engineering is an effective method to tune the band gap and electronic transport properties of graphene nanoribbons (GNRs). However, strain/stress field may promote the system deviating from the equilibrium state, and the mechanical stability will become one of the key issues for reliable services of relevant devices. In this paper, the size-dependent mechanical properties of GNRs under tensile loading were studied by Molecular Dynamics (MD) simulations. The results indicate that the yield stress of both zigzag and armchair GNRs decreases with the ribbon length changing from 240 Å to 30 Å. However, the ductility of armchair GNRs was significantly improved. Radial Distribution Function (RDF) was employed to analyze the evolution of atomic configurations. It showed that lattice shearing is the main mechanism for the ductility of armchair GNRs.

scholarly journals STUDY OF PRISTINE CARBON NANOTUBE UNDER TENSILE AND COMPRESSIVE LOADS USING MOLECULAR DYNAMICS SIMULATION

2010 ◽  
Vol 40 (2) ◽  
pp. 72-78 ◽  
Author(s):  
S. N. Hossain Rubaiyat ◽  
Sanjib Chandra Chowdhury
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Equations Of Motion ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Strength Failure ◽  
Compressive Loads ◽  
Brenner Potential ◽  
Very High

After the discovery, carbon nanotubes (CNTs) have received tremendous scientific and industrial interests. This is due to their exceptional mechanical, electrical, and thermal properties. CNTs having pristine structure (i.e., structure without any defect) hold very high mechanical properties. In this article, mechanical properties of CNTs are studied under both tensile and compressive loads using molecular dynamics (MD) simulations. Four armchair single-walled nanotubes (SWNTs) having indexes of (3,3), (4,4), (5,5) and (6,6) with pristine structure are simulated with MD. Molecular simulations are carried out using the classical MD method, in which the Newtonian equations of motion are solved numerically for a set of atoms. The velocity- Verlet algorithm is used for solving the Newtonian equations of motion. The Brenner potential is used for carbon-carbon interaction in the CNT and temperature of the system is controlled by velocity scaling. Simulation results show that modulus of elasticity of CNTs varies significantly with CNT diameter. The results obtained from the compressive test by MD simulations are in well agreement with the results obtained from theoretical Euler equation and parabolic equation for long and short column respectively.Keywords: Carbon nanotubes; Molecular dynamics; Young’s modulus; Failure strength; Failure strain.DOI: 10.3329/jme.v40i2.5346Journal of Mechanical Engineering, Vol. ME 40, No. 2, December 2009 72-78

scholarly journals Understanding Covalent Grafting of Nanotubes onto Polymer Nanocomposites: Molecular Dynamics Simulation Study

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2621
Author(s):  
Seunghwa Yang
Keyword(s):  
Molecular Dynamics ◽  
Load Transfer ◽  
Cell Model ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Covalent Grafting ◽  
Modelling Strategies ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
External Loads

Here, we systematically interrogate the effects of grafting single-walled (SWNT) and multi-walled carbon nanotubes (MWNT) to polymer matrices by using molecular dynamics (MD) simulations. We specifically investigate key material properties that include interfacial load transfer, alteration of nanotube properties, and dispersion of nanotubes in the polymer matrix. Simulations are conducted on a periodic unit cell model of the nanocomposite with a straight carbon nanotube and an amorphous polyethylene terephthalate (PET) matrix. For each type of nanotube, either 0%, 1.55%, or 3.1% of the carbon atoms in the outermost nanotubes are covalently grafted onto the carbon atoms of the PET matrix. Stress-strain curves and the elastic moduli of nanotubes and nanocomposites are determined based on the density of covalent grafting. Covalent grafting promotes two rivalling effects with respect to altering nanotube properties, and improvements in interfacial load transfer in the nanocomposites are clearly observed. The enhanced interface enables external loads applied to the nanocomposites to be efficiently transferred to the grafted nanotubes. Covalent functionalization of the nanotube surface with PET molecules can alter the solubility of nanotubes and improve dispersibility. Finally, we discuss the current limitations and challenges in using molecular modelling strategies to accurately predict properties on the nanotube and polymers systems studied here.

A Study on the Uniaxial Tension of FCC Metals at Nano Level Using MD

2008 ◽  
Vol 32 ◽  
pp. 255-258
Author(s):  
Bohayra Mortazavi ◽  
Akbar Afaghi Khatibi
Keyword(s):  
Molecular Dynamics ◽  
Uniaxial Tension ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Face Centered Cubic ◽  
Engineering Strain ◽  
Fcc Metals ◽  
Engineering Stress ◽  
Nano Science ◽  
Face Centered

Molecular Dynamics (MD) are now having orthodox means for simulation of matter in nano-scale. It can be regarded as an accurate alternative for experimental work in nano-science. In this paper, Molecular Dynamics simulation of uniaxial tension of some face centered cubic (FCC) metals (namely Au, Ag, Cu and Ni) at nano-level have been carried out. Sutton-Chen potential functions and velocity Verlet formulation of Noise-Hoover dynamic as well as periodic boundary conditions were applied. MD simulations at different loading rates and temperatures were conducted, and it was concluded that by increasing the temperature, maximum engineering stress decreases while engineering strain at failure is increasing. On the other hand, by increasing the loading rate both maximum engineering stress and strain at failure are increasing.

Molecular Dynamics Simulation of Crack Initiation of Aluminum under Tensile Deformation

2011 ◽  
Vol 378-379 ◽  
pp. 7-10
Author(s):  
Gui Xue Bian ◽  
Yue Liang Chen ◽  
Jian Jun Hu ◽  
Li Xu
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Elastic Constants ◽  
Tensile Deformation ◽  
Crack Nucleation ◽  
Tensile Load ◽  
Dynamics Simulation ◽  
Metal Aluminum ◽  
Impurity Metal

Molecular dynamics simulation was used to simulate the tension process of purity and containing impurity metal aluminum. Elastic constants of purity and containing impurity metal aluminum were calculated, and the effects of impurity on the elastic constants were also studied. The results show that O-Al bond and Al-Al bond near oxygen atoms could be the sites of crack nucleation or growth under tensile load, the method can be extended to research mechanical properties of other metals and alloys structures.

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