Do Reuss and Voigt Bounds Really Bound in High-Pressure Rheology Experiments?
Energy dispersive synchrotron x-ray diffraction is carried out to measure differential lattice strains in polycrystalline Fe{sub 2}SiO{sub 4} (fayalite) and MgO samples using a multi-element solid state detector during high-pressure deformation. The theory of elastic modeling with Reuss (iso-stress) and Voigt (iso-strain) bounds is used to evaluate the aggregate stress and weight parameter, {alpha} (0{le}{alpha}{le}1), of the two bounds. Results under the elastic assumption quantitatively demonstrate that a highly stressed sample in high-pressure experiments reasonably approximates to an iso-stress state. However, when the sample is plastically deformed, the Reuss and Voigt bounds are no longer valid ({alpha} becomes beyond 1). Instead, if plastic slip systems of the sample are known (e.g. in the case of MgO), the aggregate property can be modeled using a visco-plastic self-consistent theory.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 914166
- Report Number(s):
- BNL-78734-2007-JA; JCOMEL; TRN: US0801588
- Journal Information:
- J. Phys.: Condens. Matter, Vol. 18; ISSN 0953-8984
- Country of Publication:
- United States
- Language:
- English
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