Numerical Simulation of Microstructure Evolution of Rocks

FFT/ELLE

FFT/ELLE is a numerical code developed to simulate microstructure evolution of rocks during plastic deformation and recrystallization.

The numerical approach is based on the coupling of a full-field viscoplastic formulation based on the Fast Fourier Transform (Lebensohn, 2001) and a front-tracking approach using the numerical platform Elle (e.g., Bons et al., 2008). Briefly, the FFT-formulation provides an exact solution of the micromechanical problem by finding a strain-rate and stress field, associated with a kinematically admissible velocity field, which minimizes the average local work-rate under the compatibility and equilibrium constraints (see Lebensohn, 2001 and Lebensohn et al., 2008). The numerical platform ELLE is an open-source multi-purpose and multi-scale software for the simulation of the evolution of microstructures during deformation and metamorphism. ELLE has been extensively used to simulate microstructure processes, including grain growth (Bons et al., 2001; Jessell et al., 2003), dynamic recrystallization (Piazolo et al., 2002), strain localization (Jessell et al., 2005), melt processes (Becker et al., 2008), deformation of two-phase materials (Jessell et al., 2009) and porphyroclast rotation in anisotropic materials (Griera et al., 2011; Griera et al., 2013), among other contributions.

The code started to be developed during a CNRS postdoc at LMTG of Toulouse (France) under the supervision by Mark Jessell (Toulouse, France) and colaboration by Ricardo Lebensohn (LANL, USA), Lynn Evans (Monash, Australia) and Paul Bons (Tuebingen, Germany). The code is freely distributed with the Elle package, although if you want to use please contact us (albert.griera at uab.cat)

Flow diagram of the numerical scheme 

 

 

 

 

 

 

 

 

 

 





Examples 

Deformation of polycrystalline ice

 

 

 

 

 

 

 

 

 

 

 

 

(a) Lattice orientation of the microstructure (a) before and (b) after deformation. (c) Normalized strain increment and (d) Von Mises stress field.


Numerical simulation of deformation and growth of porphyroblasts

 

 


Dynamic recrystallization of Olivine

Campus d'excel·lència internacional U A B