Merge pull request #5985 from bobmyhill/stab_doc

improved documentation of elastic stabilization factor
geodynamics · Jul 26, 2024 · 6e5f0cb · 6e5f0cb
2 parents d9c9638 + c9bb6d5
commit 6e5f0cb
Showing 1 changed file with 11 additions and 7 deletions.
diff --git a/source/material_model/rheology/elasticity.cc b/source/material_model/rheology/elasticity.cc
@@ -95,13 +95,17 @@ namespace aspect
         prm.declare_entry ("Stabilization time scale factor", "1.",
                            Patterns::Double (1.),
                            "A stabilization factor for the elastic stresses that influences how fast "
-                           "elastic stresses adjust to deformation. 1.0 is equivalent to no stabilization "
-                           "and may lead to oscillatory motion. Setting the factor to 2 "
-                           "avoids oscillations, but still enables an immediate elastic response. "
-                           "However, in complex models this can lead to problems of convergence, in which "
-                           "case the factor needs to be increased slightly. Setting the factor to "
-                           "infinity is equivalent to not applying elastic stresses at all. The "
-                           "factor is multiplied with the computational time step to create a time scale. ");
+                           "elastic stresses adjust to deformation. This value is equal to the "
+                           "elastic time step divided by the computational time step. "
+                           "The default value of 1.0 may lead to oscillatory motion. "
+                           "Increasing this factor to 2.0 can reduce oscillations while "
+                           "preserving an immediate elastic response. In complex models the factor "
+                           "can be increased further to improve convergence behaviour. "
+                           "As the stabilization factor increases, the effective viscosity "
+                           "gets smaller, and is balanced by an increasing body force term. "
+                           "For composite rheologies that use this formulation of elasticity, "
+                           "setting an infinite shear modulus only recovers the nonelastic part of "
+                           "the rheology if this stabilization factor is equal to 1.0.");
         prm.declare_entry ("Elastic damper viscosity", "0.0",
                            Patterns::Double (0.),
                            "Viscosity of a viscous damper that acts in parallel with the elastic "