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--- solvers:stress [2012/11/20 21:39]
gag [General Informations]
+++ solvers:stress [2016/01/20 09:34] (current)
gag [General Description]
@@ Line 12: / Line 12: @@
 ==== General Description ====
-The aim of this solver is to compute deviatoric or Cauchy stress from flow solution. For a 2D simulation there are 4 DOFs (S11, S22, S33, S12), for a 3D simulation, 2 additional are being solved for (S11, S22, S33, S12, S23, S31). This solver uses a dummy variable and solves 4 (6 in 3D) times a 1 DOF system for each stress components.
+The aim of this solver is to compute deviatoric or Cauchy stress from flow solution. For a 2D simulation there are 4 DOFs ''(S11, S22, S33, S12)'', for a 3D simulation, 2 additional are being solved for ''(S11, S22, S33, S12, S23, S31)''. This solver uses a dummy variable and solves 4 (6 in 3D) times a 1 DOF system for each stress components.
 The Cauchy stress is computed using:\\
@@ Line 18: / Line 18: @@
 <m>sigma_{ij}  = 2 {eta}  {epsilon}_{ij} - p delta_{ij} </m> \\
-where <m>epsilon</m> is directly evaluated from the velocity field and <m>p</m> is the isotropic pressure.
+where <m>epsilon</m> is directly evaluated from the velocity field and <m>p</m> is the isotropic pressure.The convention is that a positive stress corresponds to a tensile stress (opposite to the isotropic pressure convention).
+This solver doesn't work for the GOLF anisotropic ([[solvers:aiflow|AIFlow Solver]]) and the snow/firn ([[solvers:porous|Porous Solver]]) rheologies. Nevertheless, these two solvers have intrinsic functions which allow to compute the stress directly.
@@ Line 26: / Line 28: @@
 Solver 1
   Equation = String "StressSolver"
-  Procedure =  File "ComputeDevStressNS" "ComputeDevStress"
+  Procedure =  File "ElmerIceSolvers" "ComputeDevStress"
   ! this is just a dummy, hence no output is needed
   !-----------------------------------------------------------------------
@@ Line 34: / Line 36: @@
   !-----------------------------------------------------------------------
   Flow Solver Name = String "Flow Solution"
-  ! the name of the stress solution (default is 'stress')
+  ! no default value anymore for "Stress Variable Name"
   Stress Variable Name = String 'Sigma'
   !-----------------------------------------------------------------------
@@ Line 58: / Line 60: @@
 ==== Examples ====
-Download an example using this solver. TODO
+A 2D example can be found in ''[ELMER_TRUNK]/elmerice/Tests/ComputeDevStress''.
 ==== Reference ====
-When used this solver can be cited using the following references:\\
+This solver can be cited using the following references:\\
 Gagliardini O., D. Cohen, P. Råback and T. Zwinger, 2007. Finite-Element Modeling of Subglacial Cavities and Related Friction Law. J. of Geophys. Res.,  Earth Surface, 112, F02027.

solvers/stress.1353447588.txt.gz · Last modified: 2012/11/20 21:39 by gag

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