Investigation of dislocation density evolution during simulated metallic microparticle impacts
ORAL
Abstract
Accurately modeling the rate-dependent plastic deformation of metals across a large
range of strain rates requires a comprehensive accounting of dislocation motion and evolution.
The newly developed analytical dislocation evolution model of Hunter and Preston, accounts for
a wide range of dislocation annihilation and nucleation mechanisms including: network storage,
Frank-Read sources, cross-slip, double cross-slip, mobile-immobile annihilation, grain boundary
storage, grain boundary nucleation, and shock induced nucleation. In conjunction with the mean
first passage time flow stress model, this new model is able to capture the plastic behavior of
polycrystalline FCC metals across a large range of loading regimes from quasi-static to shock
loading environments. These models have been recently implemented in Los Alamos National
Laboratory’s hydrodynamics research code, FLAG. Data from quasi-static, Hopkinson bar, and
flyer plate experiments are used to create material parameter sets. Then continuum scale
microparticle impacts are simulated in FLAG and compared to experimental observations.
range of strain rates requires a comprehensive accounting of dislocation motion and evolution.
The newly developed analytical dislocation evolution model of Hunter and Preston, accounts for
a wide range of dislocation annihilation and nucleation mechanisms including: network storage,
Frank-Read sources, cross-slip, double cross-slip, mobile-immobile annihilation, grain boundary
storage, grain boundary nucleation, and shock induced nucleation. In conjunction with the mean
first passage time flow stress model, this new model is able to capture the plastic behavior of
polycrystalline FCC metals across a large range of loading regimes from quasi-static to shock
loading environments. These models have been recently implemented in Los Alamos National
Laboratory’s hydrodynamics research code, FLAG. Data from quasi-static, Hopkinson bar, and
flyer plate experiments are used to create material parameter sets. Then continuum scale
microparticle impacts are simulated in FLAG and compared to experimental observations.
*The authors would like to acknowledge funding from Lagrangian Applications Project (LAP) and Physics and Engineering Models (PEM) project under the Advanced Simulation and Computing (ASC) program at Los Alamos National Laboratory.
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Presenters
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Kevin C Larkin
- Las Alamos National Laboratory