Strain rate, temperature and representative length scale influence on plasticity and yield stress in copper [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 2011.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Additional Creators:
- Los Alamos National Laboratory
United States. Department of Energy
United States. Department of Energy. Office of Scientific and Technical Information
- Shock compression of materials constitutes a complex process involving high strain rates, elevated temperatures and compression of the lattice. Materials properties are greatly affected by temperature, the representative length scale and the strain rate of the deformation. Experimentally, it is difficult to study the dynamic microscopic mechanisms that affect materials properties following high intensity shock loading, but they can be investigated using molecular dynamics (MD) simulations. Moreover, MD allows a better control over some parameters. We are using MD simulations to study the effect of the strain rate, representative length scale and temperature on the properties of metals during compression. A half-million-atom Cu sample is subjected to strain rates ranging from 10⁷ s⁻¹ to 10¹² s⁻¹ at different temperatures ranging from 50K to 1500K. Single crystals as well as polycrystals are investigated. Plasticity mechanisms as well as the evolution of the micro- and macro-yield stress are observed. Our results show that the yield stress increases with increasing strain rate and decreasing temperature. We also show that the strain rate at which the transition between constant and increasing yield stress as a function of the temperature occurs increases with increasing temperature. Calculations at different grain sizes will give an insight into the grain size effect on the plasticity mechanisms and the yield stress.
- Published through SciTech Connect.
International Symposium on Plasticity ; January 3, 2011 ; Puerto Vallarta, Jalisco, Mexico.
Germann, Timothy C; Dupont, Virginie.
- Funding Information:
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