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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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Computational nanofluidics: nonlocal viscosity kernel
TL;DR: In this article, an extended analysis of the wavevector dependent shear viscosity of monatomic and diatomic fluids over a wide range of wavevectors and for a variety of state points is presented.
Dynamic Response Of Complex Materials Under Shock Loading
TL;DR: Arman et al. as mentioned in this paper investigated the dynamic response of complex materials under adiabatic planar shock wave loading (one-dimensional strain) with molecular dynamics simulations, including Hugoniot states, shock-induced plasticity, and spallation.
Journal ArticleDOI
Mesoscale simulations of shockwave energy dissipation via chemical reactions
TL;DR: A particle-based mesoscale model that incorporates chemical reactions at a coarse-grained level is used to study the response of materials that undergo volume-reducing chemical reactions under shockwave-loading conditions and finds that such chemical reactions can attenuate the shockwave.
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Elastic–plastic transition of compressional shocks in a perfect 2D Yukawa crystal
TL;DR: In this paper , the authors investigated the elastic-plastic transition of compressional shocks in a perfect two-dimensional Yukawa crystal and found that the maximum shear stress first increases linearly with the compressional speed until it reached its extreme value, then decreases drastically to a much lower level.
Journal ArticleDOI
Kinetics theory of shock-induced structural heterogenization
TL;DR: In this article, the mesoparticle velocity distribution function was used to determine the first and second statistical moments of the distribution function, respectively, for meso-macro energy exchange.
References
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Journal ArticleDOI
Shock-wave structure via nonequilibrium molecular dynamics and Navier-Stokes continuum mechanics
TL;DR: In this article, a strong steady dense-fluid shock wave is simulated with 4800-atom nonequilibrium molecular dynamics, and the resulting density, stress, energy, and temperature profiles are compared with corresponding macroscopic profiles derived from Navier-Stokes continuum mechanics.
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Fracture simulations using large-scale molecular dynamics
Brad Lee Holian,Ramon Ravelo +1 more
TL;DR: It is found that the can suppress ductile behavior by including viscous damping in the equations of motion, thereby demonstrating a transition to brittle crack propagation as static, zero-strain-rate conditions are approached.
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Dislocation Dynamics and Dynamic Yielding
TL;DR: In this article, the dislocation dynamics of Gilman and Johnston were applied to the problem of elastic elastic flow in Armco iron at very high strain rates, and the initial density of dislocation lines, N0, was found to be 2.0×108 cm−2.
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Large-Scale Molecular Dynamics Simulations of Three-Dimensional Ductile Failure
TL;DR: In this paper, the authors performed massively parallel 3D molecular dynamics simulations with up to 35 million atoms to investigate ductile failure, obtaining mechanistic information at the atomistic level inaccessible to experiment.
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A mechanism for dislocation generation in shock-wave deformation
TL;DR: Hornbogen as discussed by the authors proposed a modification to Smith's (9) model, based on the fact that shockloaded iron (between 7 and II GPa) presents a substructure characterized by straight screw dislocations.