From transient to steady state deformation and grain size: A thermodynamic approach using elasto-visco-plastic numerical modeling

Herwegh, Marco; Poulet, T.; Karrech, A.; Regenauer-Lieb, K. (2014). From transient to steady state deformation and grain size: A thermodynamic approach using elasto-visco-plastic numerical modeling. Journal of geophysical research, 119(2), pp. 900-918. American Geophysical Union 10.1002/2013JB010701

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Numerical simulation experiments give insight into the evolving energy partitioning during high-strain torsion experiments of calcite. Our numerical experiments are designed to derive a generic macroscopic grain size sensitive flow law capable of describing the full evolution from the transient regime to steady state. The transient regime is crucial for understanding the importance of micro structural processes that may lead to strain localization phenomena in deforming materials. This is particularly important in geological and geodynamic applications where the phenomenon of strain localization happens outside the time frame that can be observed under controlled laboratory conditions. Ourmethod is based on an extension of the paleowattmeter approach to the transient regime. We add an empirical hardening law using the Ramberg-Osgood approximation and assess the experiments by an evolution test function of stored over dissipated energy (lambda factor). Parameter studies of, strain hardening, dislocation creep parameter, strain rates, temperature, and lambda factor as well asmesh sensitivity are presented to explore the sensitivity of the newly derived transient/steady state flow law. Our analysis can be seen as one of the first steps in a hybrid computational-laboratory-field modeling workflow. The analysis could be improved through independent verifications by thermographic analysis in physical laboratory experiments to independently assess lambda factor evolution under laboratory conditions.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences
08 Faculty of Science > Other Institutions > Teaching Staff, Faculty of Science
08 Faculty of Science > Institute of Geological Sciences > Tectonics

UniBE Contributor:

Herwegh, Marco

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

0148-0227

Publisher:

American Geophysical Union

Language:

English

Submitter:

Marco Herwegh

Date Deposited:

10 Sep 2014 16:53

Last Modified:

28 Apr 2016 11:36

Publisher DOI:

10.1002/2013JB010701

BORIS DOI:

10.7892/boris.47033

URI:

https://boris.unibe.ch/id/eprint/47033

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