Journal ArticleDOI
Plasticity Induced by Shock Waves in Nonequilibrium Molecular-Dynamics Simulations
Brad Lee Holian,Peter S. Lomdahl +1 more
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TLDR
In this article, nonequilibrium molecular-dynamics simulations of shock waves in three-dimensional 10-million atom face-centered cubic crystals with cross-sectional dimensions of 100 by 100 unit cells were presented.Abstract:
Nonequilibrium molecular-dynamics simulations of shock waves in three-dimensional 10-million atom face-centered cubic crystals with cross-sectional dimensions of 100 by 100 unit cells show that the system slips along all of the available {111} slip planes, in different places along the nonplanar shock front. Comparison of these simulations with earlier ones on a smaller scale not only eliminates the possibility that the observed slippage is an artifact of transverse periodic boundary conditions, but also reveals the richness of the nanostructure left behind. By introducing a piston face that is no longer perfectly flat, mimicking a line or surface inhomogeneity in the unshocked material, it is shown that for weaker shock waves (below the perfect-crystal yield strength), stacking faults can be nucleated by preexisting extended defects.read more
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Microscopic View of Structural Phase Transitions Induced by Shock Waves
TL;DR: Multimillion-atom molecular-dynamics simulations are used to investigate the shock-induced phase transformation of solid iron, finding that the dynamics and orientation of the developing close-packed grains depend on the shock strength and especially on the crystallographic shock direction.
Journal ArticleDOI
Advances in Modeling and Simulation of Grinding Processes
Ekkard Brinksmeier,Jan C. Aurich,Edvard Govekar,Carsten Heinzel,H.-W. Hoffmeister,Fritz Klocke,Jacques Peters,R. Rentsch,David J. Stephenson,Eckart Uhlmann,Klaus Weinert,M. Wittmann +11 more
TL;DR: In this paper, the authors present an overview of the current state of the art in modeling and simulation of grinding processes: physical process models (analytical and numerical models) and empirical process models(regression analysis, artificial neural net models) as well as rule based models (rule based models) are taken into account.
Journal ArticleDOI
Ultrahigh Strength in Nanocrystalline Materials Under Shock Loading
Eduardo M. Bringa,Eduardo M. Bringa,Alfredo Caro,Alfredo Caro,Yinmin Wang,Yinmin Wang,Maximo Victoria,Maximo Victoria,James McNaney,James McNaney,Bruce Remington,Bruce Remington,Raymond F. Smith,Raymond F. Smith,Ben Torralva,Ben Torralva,Helena Van Swygenhoven,Helena Van Swygenhoven +17 more
TL;DR: Molecular dynamics simulations of nanocrystalline copper under shock loading show an unexpected ultrahigh strength behind the shock front, with values up to twice those at low pressure.
Journal ArticleDOI
Length scale and time scale effects on the plastic flow of fcc metals
TL;DR: In this paper, the authors examined size scale and strain rate effects on single-crystal face-centered cubic cubic (fcc) metals and found that dislocations nucleating at free surfaces are critical to causing micro-yield and macro-yielding in pristine material.
Journal ArticleDOI
Shock deformation of face-centred-cubic metals on subnanosecond timescales
Eduardo M. Bringa,K. Rosolankova,Robert E. Rudd,B. A. Remington,Justin Wark,Mark A. Duchaineau,Daniel H. Kalantar,James Hawreliak,James Belak +8 more
TL;DR: Large-scale molecular dynamics simulations of shock-wave propagation through a metal allowing a detailed analysis of the dynamics of high strain-rate plasticity resolve the important discrepancy in the evolution of the strain from one- to three-dimensional compression observed in diffraction experiments.
References
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Journal ArticleDOI
Detonations at nanometer resolution using molecular dynamics.
TL;DR: It is shown that discrete detonation chemistry can be studied using molecular dynamics simulations and that simulations using reactive many-body potentials provide a powerful probe of the interplay between the continuum properties of shock waves and the atomic-scale chemistry they induce in condensed-phase detonations.
BookDOI
Microscopic simulations of complex hydrodynamic phenomena
Michel Mareschal,Brad Lee Holian +1 more
TL;DR: Theoretical foundations and applications of non-equilibrium molecular dynamics have been discussed in this paper, including the use of the Direct Simulation Monte Carlo Method (DSMC) and Lattice Boltzmann Simulation of High Reynolds Number Fluid Flow in Two Dimensions.
Journal ArticleDOI
Modeling shock-wave deformation via molecular dynamics
TL;DR: In this paper, the authors show that the plastic flow that leads to shear-stress relaxation in 3D solids and fluids is highly localized near the shock front, involving slippage along close-packed planes.
Journal ArticleDOI
Effects of pairwise versus many-body forces on high-stress plastic deformation
Brad Lee Holian,Arthur F. Voter,N. J. Wagner,Ramon Ravelo,S. P. Chen,William G. Hoover,Carol Griswold Hoover,James E. Hammerberg,T. D. Dontje +8 more
TL;DR: A model embedded-atom (many-body) potential is proposed and tested against an effective, density-independent, pairwise-additive potential in a variety of nonequilibrium molecular-dynamics simulations of plastic deformation under high stress to observe significant qualitative differences in flow behavior.
Journal ArticleDOI
Structure of a Shock-Wave Front in a Liquid
TL;DR: Solutions of the Navier-Stokes equations for strong shock waves in a dense fluid agree well with recent atomistic simulations using nonequilibrium molecular dynamics as discussed by the authors, which is the state-of-the-art.