Journal ArticleDOI
Plasticity Induced by Shock Waves in Nonequilibrium Molecular-Dynamics Simulations
Brad Lee Holian,Peter S. Lomdahl +1 more
Reads0
Chats0
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
Citations
More filters
Journal Article
Molecular dynamics study of shock compression in porous silica glass
TL;DR: In this paper, the authors investigated the shock response of porous amorphous silica using classical molecular dynamics, over a range of porosity ranging from fully dense (2.21 g/cc) down to 0.14
Journal Article
Development and Application of a Nonequilibrium Molecular Dynamics Simulation Method to Study Shock Waves Propagating in Argon Gas
TL;DR: In this article, a nonequilibrium molecular dynamics (NEMD) simulation method is developed and applied to study shock waves propagating through argon gas, and a linear relationship between piston speeds and shock speeds is observed.
Journal ArticleDOI
Deviatoric stress driven transient melting below the glass transition temperature in shocked polymers
TL;DR: In this article , the authors report a transient melting of a glassy polymer under shock loading, where large deviatoric stresses near the shock front induce fast transitions in backbone dihedral angles and a stress relaxation characteristic of polymer melts.
Proceedings ArticleDOI
Molecular dynamics study of shock compression in porous silica glass
TL;DR: In this paper, the authors investigated the shock response of porous amorphous silica using classical molecular dynamics, over a range of porosity ranging from fully dense (2.21 g/cc) down to 0.14
Journal ArticleDOI
Quasiplastic Deformation in Shocked Nanocrystalline Boron Carbide: Grain Boundary Sliding and Local Amorphization
TL;DR: In this article , the authors report the shock response of nanocrystalline boron carbide (n -B 4 C) using large-scale molecular dynamics simulations with a machine-learning force field.
References
More filters
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.