Power-law viscous materials for analogue experiments: New data on the rheology of highly-filled silicone polymers

David Boutelier, Christoph Schrank, Alexander Cruden

Research output: Contribution to journalArticleResearchpeer-review

38 Citations (Scopus)

Abstract

The selection of appropriate analogue materials is a central consideration in the design of realistic physical models. We investigate the rheology of highly-filled silicone polymers in order to find materials with a power-law strain-rate softening rheology suitable for modelling rock deformation by dislocation creep and report the theological properties of the materials as functions of the filler content. The mixtures exhibit strain-rate softening behaviour but with increasing amounts of filler become strain-dependent. For the strain-independent viscous materials, flow laws are presented while for strain-dependent materials the relative importance of strain and strain rate softening/hardening is reported. If the stress or strain rate is above a threshold value some highly-filled silicone polymers may be considered linear visco-elastic (strain independent) and power-law strain-rate softening. The power-law exponent can be raised from 1 to similar to 3 by using mixtures of high-viscosity silicone and plasticine. However, the need for high shear strain rates to obtain the power-law rheology imposes some restrictions on the usage of such materials for geodynamic modelling. Two simple shear experiments are presented that use Newtonian and power-law strain-rate softening materials. The results demonstrate how materials with power-law rheology result in better strain localization in analogue experiments. (C) 2007 Elsevier Ltd. All rights reserved.
Original languageEnglish
Pages (from-to)341 - 353
Number of pages13
JournalJournal of Structural Geology
Volume30
Issue number3
DOIs
Publication statusPublished - 2008
Externally publishedYes

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