Dislocation Generation and Crack Propagation in Metals Examined in Molecular Dynamics Simulations

1992 ◽  
Vol 278 ◽  
Author(s):  
J. A. Rifkin ◽  
C. S. Becquart ◽  
D. Kim ◽  
P. C. Clapp
Keyword(s):  
Crack Propagation ◽  
Atomistic Simulations ◽  
Many Body ◽  
Dislocation Generation ◽  
Embedded Atom ◽  
Stress Levels ◽  
Different Temperatures ◽  
The Many ◽  
Dynamics Simulations ◽  
Many Body Interactions

AbstractWe have carried out a series of atomistic simulations on arrays of about 10,000 atoms containing an atomically sharp crack and subjected to increasing stress levels. The ordered stoichiometric alloys B2 NiAl, B2 RuAl and A15 Nb3AI have been studied at different temperatures and stress levels, as well as the elements Al, Ni, Nb and Ru. The many body interactions used in the simulations were derived semi-empirically, using techniques related to the Embedded Atom Method. Trends in dislocation generation rates and crack propagation modes will be discussed and compared to experimental indications where possible, and some of the simulations will be demonstrated in the form of computer movies.

Atomistic Simulation of ZrNi Metallic Glasses Under Torsion Test

NANO ◽  
2017 ◽  
Vol 12 (08) ◽  
pp. 1750094 ◽  
Author(s):  
Po-Hsien Sung ◽  
Tei-Chen Chen ◽  
Cheng-Da Wu
Keyword(s):  
Cooling Rate ◽  
Packing Density ◽  
Shear Bands ◽  
Torsion Test ◽  
Torsional Angle ◽  
Many Body ◽  
Cooling Rates ◽  
Embedded Atom ◽  
The Many ◽  
Dynamics Simulations

ZrNi metallic glass alloy nanowires (NWs) under torsion are studied using molecular dynamics simulations based on the many-body embedded-atom potential. The effect of cooling rate on the deformation mechanism and mechanical properties of ZrNi NWs is evaluated in terms of shear strain, torque, potential energy and radial distribution function. Simulation results show that for slower cooling rates, the NWs have larger packing density, whereas for faster cooling rates, the packing density of atoms decreases. The amount of deformation increases with increasing torsional angle before it reaches a critical torsional angle ([Formula: see text]. The torque required for deformation and the [Formula: see text] value increase with decreasing cooling rate, indicating a larger mechanical strength. Localized shear bands concentrate at regions with high shear strains, leading to the formation of torsional buckling.

Data-Driven Many-Body Models with Chemical Accuracy for CH4/H2O Mixtures

2020 ◽  
Author(s):  
Marc Riera ◽  
Alan Hirales ◽  
Raja Ghosh ◽  
Francesco Paesani
Keyword(s):  
Liquid Phase ◽  
Quantitative Description ◽  
Liquid Mixtures ◽  
Many Body ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Dynamics Simulations ◽  
Body Potential ◽  
Small Clusters ◽  
Many Body Interactions

<div> <div> <div> <p>Many-body potential energy functions (PEFs) based on the TTM-nrg and MB-nrg theoretical/computational frameworks are developed from coupled cluster reference data for neat methane and mixed methane/water systems. It is shown that that the MB-nrg PEFs achieve subchemical accuracy in the representation of individual many-body effects in small clusters and enables predictive simulations from the gas to the liquid phase. Analysis of structural properties calculated from molecular dynamics simulations of liquid methane and methane/water mixtures using both TTM-nrg and MB-nrg PEFs indicates that, while accounting for polarization effects is important for a correct description of many-body interactions in the liquid phase, an accurate representation of short-range interactions, as provided by the MB-nrg PEFs, is necessary for a quantitative description of the local solvation structure in liquid mixtures. </p> </div> </div> </div>

Revealing the many-body interactions and valley-polarization behavior in Re-doped MoS2 monolayers

2021 ◽  
Vol 118 (11) ◽  
pp. 113101
Author(s):  
Xiaoli Zhu ◽  
Siting Ding ◽  
Lihui Li ◽  
Ying Jiang ◽  
Biyuan Zheng ◽  
...  
Keyword(s):  
Many Body ◽  
Polarization Behavior ◽  
Valley Polarization ◽  
Mos2 Monolayers ◽  
The Many ◽  
Many Body Interactions

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.

Possible weakening of the many-body interactions in the organic quasi-two-dimensional metal α-(BETS)2NH4Hg(SCN)4

2009 ◽  
Vol 109 (4) ◽  
pp. 664-666 ◽  
Author(s):  
S. I. Pesotskiĭ ◽  
R. B. Lyubovskiĭ ◽  
M. V. Kartsovnik ◽  
W. Biberacher ◽  
N. D. Kushch ◽  
...  
Keyword(s):  
Two Dimensional ◽  
Many Body ◽  
The Many ◽  
Many Body Interactions

scholarly journals Cliques Are Bricks for k-CT Graphs

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1160
Author(s):  
Václav Snášel ◽  
Pavla Dráždilová ◽  
Jan Platoš
Keyword(s):  
Complex Networks ◽  
Simplicial Complex ◽  
Dynamic Properties ◽  
Simplicial Complexes ◽  
Many Body ◽  
Chemistry Industry ◽  
The Past ◽  
Pairwise Interactions ◽  
The Many ◽  
Many Body Interactions

Many real networks in biology, chemistry, industry, ecological systems, or social networks have an inherent structure of simplicial complexes reflecting many-body interactions. Over the past few decades, a variety of complex systems have been successfully described as networks whose links connect interacting pairs of nodes. Simplicial complexes capture the many-body interactions between two or more nodes and generalized network structures to allow us to go beyond the framework of pairwise interactions. Therefore, to analyze the topological and dynamic properties of simplicial complex networks, the closed trail metric is proposed here. In this article, we focus on the evolution of simplicial complex networks from clicks and k-CT graphs. This approach is used to describe the evolution of real simplicial complex networks. We conclude with a summary of composition k-CT graphs (glued graphs); their closed trail distances are in a specified range.

Atomistic Simulations of the Mechanical Response of Copper/Polybutadiene Joints under Stress

2009 ◽  
Vol 1224 ◽  
Author(s):  
Fidel Orlando Valega Mackenzie ◽  
Barend J. Thijsse
Keyword(s):  
Mechanical Response ◽  
Polymer System ◽  
Atomistic Simulations ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Numerical Studies ◽  
Universal Force Field ◽  
Dynamics Simulations ◽  
Metal Melting Point ◽  
Metal Polymer

AbstractMetal/polymer system joints are widely encountered nowadays in microscopic structures such as displays and microchips. In several critical cases they undergo thermal and mechanical loading, with contact failure due to fracture as a possible consequence. Because of their variety in nature and composition metal/polymer joints have become major challenges for experimental, theoretical, and numerical studies. Here we report on results of molecular dynamics simulations carried out to study the mechanical response of a metal/polymer joint, in this case the Cu/polybutadiene model system. The behavior of Cu and the cross-linked polybutadiene are modeled, respectively, by the Embedded Atom Method (EAM) and the Universal Force Field (UFF). Loading is applied under compression. Different potentials are used to describe the interactions in the metal/polymer interface, which allows us to qualitatively analyze possible mechanisms of failure in these joints, below the metal melting point and above the polymer glass transition temperatures.

scholarly journals Interfacial Water Many-body Effects Drive Structural Dynamics and Allosteric interactions in SARS-CoV-2 Main Protease Dimerization Interface

2021 ◽  
Author(s):  
Dina El Ahdab ◽  
Louis Lagardère ◽  
Theo Jaffrelot Inizan ◽  
Frédéric Célerse ◽  
Chengwen Liu ◽  
...  
Keyword(s):  
Structural Dynamics ◽  
Adaptive Sampling ◽  
Many Body ◽  
Allosteric Site ◽  
Allosteric Interactions ◽  
Main Protease ◽  
Dimerization Interface ◽  
Bond Network ◽  
Dynamics Simulations ◽  
Many Body Interactions

Following our previous work (Chem. Sci., 2021, 12, 4889 – 4907), we study the structural dynamics of the SARS-CoV-2 Main Protease dimerization interface (apo dimer) by means of microsecond adaptive sampling molecular dynamics simulations (50 microseconds) using the AMOEBA polarizable force field (PFF). This interface is structured by a complex H-bond network that is only stable at physiological pH. Structural correlations analysis between its residues and the catalytic site confirms the presence of a buried allosteric site. However, noticeable differences in allosteric connectivity are observed between PFFs and non-PFFs. Interfacial polarizable water molecules are shown to appear at the heart of this discrepancy, since they are connected to the global interface H-bond network and able to adapt their dipole moment (and dynamics) to their diverse local physico-chemical micro-environments. The water-interface many-body interactions appear to drive the interface volume fluctuations and to therefore mediate the allosteric interactions with the catalytic cavity.

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