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Title: Strain-rate dependence of ramp-wave evolution and strength in tantalum

Abstract

We have conducted molecular dynamics (MD) simulations of quasi-isentropic ramp-wave compression to very high pressures over a range of strain rates from 10 11 down to 10 8 1/s. Using scaling methods, we collapse wave profiles from various strain rates to a master profile curve, which shows deviations when material response is strain-rate dependent. Thus, we can show with precision where, and how, strain-rate dependence affects the ramp wave. We find that strain rate affects the stress-strain material response most dramatically at strains below 20%, and that above 30% strain the material response is largely independent of strain rate. We show good overall agreement with experimental stress-strain curves up to approximately 30% strain, above which simulated response is somewhat too stiff. We postulate that this could be due to our interatomic potential or to differences in grain structure and/or size between simulation and experiment. Strength is directly measured from per-atom stress tensor and shows significantly enhanced elastic response at the highest strain rates. As a result, this enhanced elastic response is less pronounced at higher pressures and at lower strain rates.

Authors:
 [1];  [1];  [1];  [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1398378
Alternate Identifier(s):
OSTI ID: 1306695
Report Number(s):
SAND2017-0790J
Journal ID: ISSN 2469-9950; PRBMDO; 656110; TRN: US1702724
Grant/Contract Number:  
AC04-94AL85000
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 94; Journal Issue: 6; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Lane, J. Matthew D., Foiles, Stephen M., Lim, Hojun, and Brown, Justin L. Strain-rate dependence of ramp-wave evolution and strength in tantalum. United States: N. p., 2016. Web. doi:10.1103/PhysRevB.94.064301.
Lane, J. Matthew D., Foiles, Stephen M., Lim, Hojun, & Brown, Justin L. Strain-rate dependence of ramp-wave evolution and strength in tantalum. United States. doi:10.1103/PhysRevB.94.064301.
Lane, J. Matthew D., Foiles, Stephen M., Lim, Hojun, and Brown, Justin L. Thu . "Strain-rate dependence of ramp-wave evolution and strength in tantalum". United States. doi:10.1103/PhysRevB.94.064301. https://www.osti.gov/servlets/purl/1398378.
@article{osti_1398378,
title = {Strain-rate dependence of ramp-wave evolution and strength in tantalum},
author = {Lane, J. Matthew D. and Foiles, Stephen M. and Lim, Hojun and Brown, Justin L.},
abstractNote = {We have conducted molecular dynamics (MD) simulations of quasi-isentropic ramp-wave compression to very high pressures over a range of strain rates from 1011 down to 108 1/s. Using scaling methods, we collapse wave profiles from various strain rates to a master profile curve, which shows deviations when material response is strain-rate dependent. Thus, we can show with precision where, and how, strain-rate dependence affects the ramp wave. We find that strain rate affects the stress-strain material response most dramatically at strains below 20%, and that above 30% strain the material response is largely independent of strain rate. We show good overall agreement with experimental stress-strain curves up to approximately 30% strain, above which simulated response is somewhat too stiff. We postulate that this could be due to our interatomic potential or to differences in grain structure and/or size between simulation and experiment. Strength is directly measured from per-atom stress tensor and shows significantly enhanced elastic response at the highest strain rates. As a result, this enhanced elastic response is less pronounced at higher pressures and at lower strain rates.},
doi = {10.1103/PhysRevB.94.064301},
journal = {Physical Review B},
number = 6,
volume = 94,
place = {United States},
year = {Thu Aug 25 00:00:00 EDT 2016},
month = {Thu Aug 25 00:00:00 EDT 2016}
}

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Cited by: 1 work
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Works referenced in this record:

Analysis of shockless dynamic compression data on solids to multi-megabar pressures: Application to tantalum
journal, November 2014

  • Davis, Jean-Paul; Brown, Justin L.; Knudson, Marcus D.
  • Journal of Applied Physics, Vol. 116, Issue 20, Article No. 204903
  • DOI: 10.1063/1.4902863