COMPUTATIONAL STUDY OF TENSILE DEFORMATION OF A CONSTRAINED NANOSCALE METALLIC GLASS

2010 ◽  
Vol 24 (01n02) ◽  
pp. 305-310 ◽  
Author(s):  
JIANJUN PANG ◽  
MING-JEN TAN ◽  
KIM-MEOW LIEW
Keyword(s):  
Metallic Glass ◽  
Tensile Deformation ◽  
Surface Effect ◽  
Computational Study ◽  
Large Fraction ◽  
Tensile Load ◽  
Dynamics Simulation ◽  
Metal Nanowires ◽  
Embedded Atom ◽  
Shear Transformation Zones

In this study a nanometer-sized metallic glass (nano-MG) Ti 50 Cu 50 was generated with constrained atoms at both ends and was extended until fracture under a tensile load by molecular dynamics simulation using the general embedded-atom model (GEAM) potential. Totally different mechanical behavior was observed in the nano-MG, such as strain hardening and necking, both of which have been discovered in a few real and simulated MGs and can be related to the generation of shear transformation zones (STZs). A dramatic drop in Young's modulus was found due to the surface effect. Such effect results from the large fraction of surface atoms which have a different surrounding configuration from bulk atoms. At fracture the nano-MG breaks by atomic separation as reported in metal nanowires. The fracture strain is as large as about 120%, indicating that nano-MGs are intrinsically ductile.

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.

Molecular Dynamics Simulation of Surface Effect on Tensile Deformation of Single Crystalline Copper

2014 ◽  
Vol 620 ◽  
pp. 61-66 ◽  
Author(s):  
Qiang Gao ◽  
Yong Bo Guo ◽  
Ying Chun Liang ◽  
Qing Chun Zhang
Keyword(s):  
Molecular Dynamics ◽  
Tensile Deformation ◽  
Surface Effect ◽  
High Energy ◽  
Dislocation Nucleation ◽  
Atomic Scale ◽  
Dynamics Simulation ◽  
Crystal Plane ◽  
Single Crystalline ◽  
Tensile Process

Based on molecular dynamics method, the tensile process of single crystalline Cu nanorod and single crystalline Cu bulk were simulated at atomic scale. The motion of atoms, total energy of atom-strain curves and number of dislocation atom-strain curves during the tensile process were acquired. The results shown that surface effect has a significant effect on the tensile mechanical properties of single crystalline Cu nanorod. For single crystalline Cu nanorod, the energy of atoms in the edges and surface were higher than the energy of atoms inside the nanorod. Dislocations nucleation in the edges that with high energy and extend along the {111} crystal plane. The nanorods produce plastic deformation and shows excellent ductility under the "dislocation nucleation-energy rising and dislocation layers cross-slip" mechanism of the alternating cycle. For single crystalline Cu bulk, dislocation nucleation randomly and extend to the entire simulation model along the {111} crystal plane quickly. The single crystalline bulk Cu produce fracture under the "microscopic vacancy-microscopic hole-penetration of microscopic holes-fracture" mechanism.

Molecular-Dynamics Modelling of the Tensile Deformation of Helical Nanowires

2003 ◽  
Vol 778 ◽  
Author(s):  
K. Shintani ◽  
S. Kameoka
Keyword(s):  
Molecular Dynamics ◽  
Tensile Deformation ◽  
Axial Direction ◽  
Dynamics Simulation ◽  
Single Atom ◽  
Helical Structures ◽  
Embedded Atom ◽  
Atom Chain ◽  
Au Nanowires ◽  
Embedded Atom Method Potential

AbstractDeformations of Au nanowires of helical structures under enforced elongation are addressed by the molecular-dynamics simulation. The embedded-atom method potential is employed for calculating the interaction between Au atoms. Model nanowires of the two kinds of helicities are prepared. Before elongation, a model nanowire is equilibrated at a specified temperature. Then, the Au atoms at one end of the nanowire are translationally moved in the axial direction. The simulation results show that a model nanowire can be elongated to form a single-atom chain of Au atoms under some circumstances.

scholarly journals Computational Study on Selective PDE9 Inhibitors on PDE9-Mg/Mg, PDE9-Zn/Mg, and PDE9-Zn/Zn Systems

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 709
Author(s):  
Dakshinamurthy Sivakumar ◽  
Sathish-Kumar Mudedla ◽  
Seonghun Jang ◽  
Hyunjun Kim ◽  
Hyunjin Park ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Erectile Dysfunction ◽  
Molecular Docking ◽  
Molecular Dynamics Simulation ◽  
Cardiovascular Diseases ◽  
Neurodegenerative Disorders ◽  
Computational Study ◽  
Dynamics Simulation ◽  
Interaction Patterns

PDE9 inhibitors have been studied to validate their potential to treat diabetes, neurodegenerative disorders, cardiovascular diseases, and erectile dysfunction. In this report, we have selected highly potent previously reported selective PDE9 inhibitors BAY73-6691R, BAY73-6691S, 28r, 28s, 3r, 3s, PF-0447943, PF-4181366, and 4r to elucidate the differences in their interaction patterns in the presence of different metal systems such as Zn/Mg, Mg/Mg, and Zn/Zn. The initial complexes were generated by molecular docking followed by molecular dynamics simulation for 100 ns in triplicate for each system to understand the interactions’ stability. The results were carefully analyzed, focusing on the ligands’ non-bonded interactions with PDE9 in different metal systems.

scholarly journals Soft Ferromagnetic Bulk Metallic Glass with Potential Self-Healing Ability

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1319
Author(s):  
Parthiban Ramasamy ◽  
Mihai Stoica ◽  
Gabriel Ababei ◽  
Nicoleta Lupu ◽  
Jürgen Eckert
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Vital Role ◽  
Self Healing ◽  
Local Melting ◽  
Mold Casting ◽  
Soft Ferromagnetic ◽  
Molten Droplets ◽  
Shear Transformation Zones ◽  
Ferromagnetic Bulk

A new concept of soft ferromagnetic bulk metallic glass (BMG) with self-healing ability is proposed. The specific [Fe36Co36B19.2Si4.8Nb4]100−x(Ga)x (x = 0, 0.5, 1 and1.5) BMGs prepared by copper mold casting were investigated as a function of Ga content. The Ga-containing BMGs still hold soft magnetic properties and exhibit large plastic strain of 1.53% in compression. Local melting during shearing produces molten droplets of several µm size throughout the fracture surface. This concept of local melting during shearing can be utilized to produce BMGs with self-healing ability. The molten regions play a vital role in deflecting shear transformation zones, thereby enhancing the mechanical properties.

Simulation of Stress Distribution and Mechanical Response of Metallic Glasses

1998 ◽  
Vol 554 ◽  
Author(s):  
Y. Kogure ◽  
M. Doyama
Keyword(s):  
Stress Distribution ◽  
Metallic Glasses ◽  
Mechanical Response ◽  
Local Density ◽  
Glassy State ◽  
Dynamics Simulation ◽  
Single Atom ◽  
Atomic Interaction ◽  
Embedded Atom ◽  
Embedded Atom Method Potential

AbstractMolecular dynamics simulation of the metallic glasses has been done. The embedded atom method potential function for copper is used to express the atomic interaction. The stress distribution in the glassy state is evaluated from specific volume occupied by single atom and local density in divided cells. The displacements of individual atom under the shear stress are calculated and the correlation between the displacements and the atomic volumes are investigated.

Molecular Dynamics Simulation of Sputtering with Mmany-Body Interactions

1988 ◽  
Vol 100 ◽  
Author(s):  
Davy Y. Lo ◽  
Tom A. Tombrello ◽  
Mark H. Shapiro ◽  
Don E. Harrison
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Single Crystal ◽  
Low Energy ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Many Body ◽  
Embedded Atom ◽  
Dynamics Simulations ◽  
Small Single Crystal

ABSTRACTMany-body forces obtained by the Embedded-Atom Method (EAM) [41 are incorporated into the description of low energy collisions and surface ejection processes in molecular dynamics simulations of sputtering from metal targets. Bombardments of small, single crystal Cu targets (400–500 atoms) in three different orientations ({100}, {110}, {111}) by 5 keV Ar+ ions have been simulated. The results are compared to simulations using purely pair-wise additive interactions. Significant differences in the spectra of ejected atoms are found.

Tensile deformation micromechanisms for bulk metallic glass matrix composites: From work-hardening to softening

2011 ◽  
Vol 59 (10) ◽  
pp. 4126-4137 ◽  
Author(s):  
J.W. Qiao ◽  
A.C. Sun ◽  
E.W. Huang ◽  
Y. Zhang ◽  
P.K. Liaw ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Work Hardening ◽  
Glass Matrix ◽  
Tensile Deformation ◽  
Matrix Composites ◽  
Glass Matrix Composites

scholarly journals Computational study of smoke flow control in garage fires and optimization of the ventilation system

2009 ◽  
Vol 13 (1) ◽  
pp. 69-78
Author(s):  
Milos Banjac ◽  
Barbara Nikolic
Keyword(s):  
Computational Study ◽  
Ventilation System ◽  
Operating Mode ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
Start Time ◽  
Combustion Dynamics ◽  
Operating Modes ◽  
Smoke Flow ◽  
Emergency Operating

With the aim of evaluating capabilities of a ventilation system to control the spread of smoke in the emergency operating mode, thereby providing conditions for safe evacuation of people from a fire-struck area, computational fluid dynamics simulation of a fire in a semi-bedded garage was conducted. Using the experimental results of combustion dynamics of a passenger car on fire, optimal positions of ventilation openings were determined. According to recommendations by DIN EN 12101 standard, the operating modes of a ventilation system were verified and optimal start time of the smoke extraction system was defined.

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