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Extension of plasticity theory to debonding, grain dissolution, and chemical damage of calcarenites
Author(s) -
Ciantia Matteo O.,
Prisco Claudio
Publication year - 2015
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.2397
Subject(s) - dissolution , plasticity , materials science , constitutive equation , diagenesis , hardening (computing) , stiffness , geotechnical engineering , composite material , geology , structural engineering , mineralogy , chemistry , engineering , finite element method , layer (electronics)
Summary The mechanical properties of calcarenites are known to be significantly affected by water saturation: both stiffness and strength decrease for wetting in the short term and for chemical dissolution in the long term. Both processes mainly affect bonds among grains: immediately after inundation depositional bonds fall in suspension, whereas diagenetic bonds dissolve more slowly. In this paper, the authors started from the micro‐structural analysis of the weathering processes to conceive a strain hardening hydro‐chemo‐mechanical coupled elastoplastic constitutive model. The concept of extended hardening rules is here enriched: weathering functions have been determined by employing a micro to macro simplified upscaling procedure. Chemical damage is incorporated into the formulation by means of a scalar damage function. Its evolution is also described by using a multiscale approach. A new term is added to the strain rate tensor in order to incorporate the dissolution induced chemical deformations developing once the soft rock is turned into a granular material. A calibration procedure for the constitutive parameters is suggested, and the model is validated by using both coupled and uncoupled chemo‐mechanical experimental test results. Copyright © 2015 John Wiley & Sons, Ltd.