Untitled

Belak, J.

doi:10.1023/a:1026005627441

Cited by 19 publications

(4 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus far, a proof of principle SAXS measurement has been made in a static experiment on recovered, incipiently spalled titanium at the Advanced Photon Source [62]. Also, tomography has been used to map the locations and sizes of voids under static conditions also using recovered, incipiently spalled samples [63]. Because of the need for x-rays from multiple lines of sight, tomography during dynamic fracture is more challenging but not completely out of the question.…”

Section: Void Volumementioning

confidence: 99%

Void growth in bcc metals simulated with molecular dynamics using the Finnis–Sinclair potential

Rudd

2009

Philosophical Magazine

View full text Add to dashboard Cite

The process of fracture in ductile metals involves the nucleation, growth, and linking of voids. This process takes place both at the low rates involved in typical engineering applications and at the high rates associated with dynamic fracture processes such as spallation. Here we study the growth of a void in a single crystal at high rates using molecular dynamics (MD) based on Finnis-Sinclair interatomic potentials for the body-centred cubic (bcc) metals V, Nb, Mo, Ta, and W. The use of the Finnis-Sinclair potential enables the study of plasticity associated with void growth at the atomic level at room temperature and strain rates from 10 9 /s down to 10 6 /s and systems as large as 128 million atoms. The atomistic systems are observed to undergo a transition from twinning at the higher end of this range to dislocation flow at the lower end. We analyze the simulations for the specific mechanisms of plasticity associated with void growth as dislocation loops are punched out to accommodate the growing void. We also analyse the process of nucleation and growth of voids in simulations of nanocrystalline Ta expanding at different strain rates. We comment on differences in the plasticity associated with void growth in the bcc metals compared to earlier studies in face-centred cubic (fcc) metals.

show abstract

Section: Void Volumementioning

confidence: 99%

Void growth in bcc metals simulated with molecular dynamics using the Finnis–Sinclair potential

Rudd

2009

Philosophical Magazine

View full text Add to dashboard Cite

show abstract

“…It gives a possibility to perform a detailed study of fracture initiation during the dynamic loading. [19][20][21][22] Unfortunately, the system size in MD is now limited by 1 m 3 and the simulation time is limited by several nanoseconds even for the high-end supercomputers. At strain rates typical for experiments, the characteristic time scales are microseconds and spatial scales are several cubic micrometers.…”

Section: Introductionmentioning

confidence: 99%

Theory and molecular dynamics modeling of spall fracture in liquids

et al. 2010

View full text Add to dashboard Cite

The model of fracture of liquid under tension is developed. It is based on the "nucleation-and-growth" approach introduced initially by D. R. Curran et al. ͓Phys. Rep. 147, 253 ͑1987͔͒. The model derives the kinetics of fracture at mesoscale from the kinetics of elementary processes of void nucleation and growth in metastable liquid. The kinetics of nucleation and growth of voids in highly metastable liquid is studied in molecular dynamics ͑MD͒ simulations with the Lennard-Jones interatomic potential. The fracture under dynamic loading is considered, when the homogeneous void nucleation is relevant. The model is applied to the estimation of the spall strength of liquid. The growth of nanometer-size voids is shown to be well described by the Rayleigh-Plesset equation. The calculations of the void size distribution by the proposed kinetic model are in agreement with the distributions obtained in the direct large-scale MD simulations. The spall strength evaluated by the model is in a good agreement with the experimental data ͑the shock wave tests on hexane͒ and the direct MD simulations. The correspondence between our results on nucleation rate and the predictions of the classical nucleation theory is discussed.

show abstract

“…[21][22][23][24] Void nucleation in metals under shock loading has been extensively studied by means of molecular dynamics. [25][26][27][28][29][30] While these studies are remarkable for the fidelity and insights that they afford, including the role of inclusions, second-phase particles, dislocations, grain boundaries, and other microstructural features, they often fail to supply an analytical description of nucleation rates that can be effectively integrated into a larger multiscale framework. The present work is primarily concerned with that objective.…”

Section: Introductionmentioning

confidence: 99%

Nanovoid nucleation by vacancy aggregation and vacancy-cluster coarsening in high-purity metallic single crystals

2011

View full text Add to dashboard Cite

A numerical model to estimate critical times required for nanovoid nucleation in high-purity aluminum single crystals subjected to shock loading is presented. We regard a nanovoid to be nucleated when it attains a size sufficient for subsequent growth by dislocation-mediated plasticity. Nucleation is assumed to proceed by means of diffusion-mediated vacancy aggregation and subsequent vacancy cluster coarsening. Nucleation times are computed by a combination of lattice kinetic Monte Carlo simulations and simple estimates of nanovoid cavitation pressures and vacancy concentrations. The domain of validity of the model is established by considering rate-limiting physical processes and theoretical strength limits. The computed nucleation times are compared to experiments suggesting that vacancy aggregation and cluster coarsening are feasible mechanisms of nanovoid nucleation in a specific subdomain of the pressure-strain rate-temperature space.

show abstract

Untitled

Cited by 19 publications

References 22 publications

Void growth in bcc metals simulated with molecular dynamics using the Finnis–Sinclair potential

Void growth in bcc metals simulated with molecular dynamics using the Finnis–Sinclair potential

Theory and molecular dynamics modeling of spall fracture in liquids

Nanovoid nucleation by vacancy aggregation and vacancy-cluster coarsening in high-purity metallic single crystals

Contact Info

Product

Resources

About