[cig-commits] r16797 - short/3D/PyLith/trunk/examples/3d/hex8

[willic3 at geodynamics.org]

Author: willic3
Date: 2010-05-26 19:32:44 -0700 (Wed, 26 May 2010)
New Revision: 16797

Added:
   short/3D/PyLith/trunk/examples/3d/hex8/step11.cfg
Log:
Added an example with static friction where slip occurs.
The solution appears to be correct, but the nonlinear solution fails to
converge in 50 iterations.
It's possible we need to either increase the maximum number of iterations,
change other nonlinear solution parameters, or change the amount of
applied displacement.



Added: short/3D/PyLith/trunk/examples/3d/hex8/step11.cfg
===================================================================
--- short/3D/PyLith/trunk/examples/3d/hex8/step11.cfg	                        (rev 0)
+++ short/3D/PyLith/trunk/examples/3d/hex8/step11.cfg	2010-05-27 02:32:44 UTC (rev 16797)
@@ -0,0 +1,150 @@
+# -*- Python -*-
+[pylithapp]
+
+# ----------------------------------------------------------------------
+# PROBLEM DESCRIPTION
+# ----------------------------------------------------------------------
+
+#
+# This problem demonstrates the use of static fault friction.
+# The problem is identical to example 11, except that in this case,
+# enough displacement is applied to induce slip on the fault.
+
+# ----------------------------------------------------------------------
+# RUNNING THE SIMULATON
+# ----------------------------------------------------------------------
+
+# This is not a self-contained simulation configuration file. This
+# file only specifies parameters specific to tutorial step11.
+# The general parameters are specificed in the pylithapp.cfg
+# file which PyLith reads by default.
+#
+# To run the simulation:
+# pylith step11.cfg
+#
+# Output will be directed to the directory step11.
+
+# ----------------------------------------------------------------------
+# problem
+# ----------------------------------------------------------------------
+[pylithapp.timedependent]
+# Set bc to an array of 3 boundary conditions: 'x_pos','x_neg', and 'z_neg'.
+bc = [x_pos,x_neg,z_neg]
+
+# Set interfaces to an array of 1 fault: 'fault'.
+interfaces = [fault]
+
+[pylithapp.timedependent.implicit]
+# Set the output to an array of 2 output managers.
+# We will output the solution over the domain and the ground surface.
+output = [domain,subdomain]
+
+# Set subdomain component to OutputSolnSubset (boundary of the domain).
+output.subdomain = pylith.meshio.OutputSolnSubset
+
+# Fault friction is a nonlinear problem so we need to use the nonlinear
+# solver.
+solver = pylith.problems.SolverNonlinear
+
+# ----------------------------------------------------------------------
+# boundary conditions
+# ----------------------------------------------------------------------
+# Set the parameters for Dirichlet boundary conditions applied on the
+# +x, -x, and -z faces of the box.
+#
+# We fix the x and y degrees of freedom on the +x and -x faces, and
+# fix the z degree of freedom on the bottom (-z) face.
+#
+# For x_pos and x_neg, we change the database from ZeroDispDB (which
+# specifies a zero value) to UniformDB, which allows us to provide
+# displacement values within the .cfg file.
+#
+# For z_neg, we keep the default ZeroDispDB, since we just want zero
+# z-displacements on that boundary.
+#
+# Note that since the fault cuts through the base of the model (z_neg),
+# we can only constrain the portion of the bottom boundary that does not
+# include the fault. A nodeset named 'face_zneg_nofault' has been defined
+# in Cubit for this purpose.
+#
+
+# The label corresponds to the name of the nodeset in CUBIT.
+
+# +x face
+[pylithapp.timedependent.bc.x_pos]
+bc_dof = [0, 1]
+label = face_xpos
+db_initial = spatialdata.spatialdb.UniformDB
+db_initial.label = Dirichlet BC on +x
+db_initial.values = [displacement-x,displacement-y]
+db_initial.data = [0.0*cm,-10.0*cm]
+
+# -x face
+[pylithapp.timedependent.bc.x_neg]
+bc_dof = [0, 1]
+label = face_xneg
+db_initial = spatialdata.spatialdb.UniformDB
+db_initial.label = Dirichlet BC on -x
+db_initial.values = [displacement-x,displacement-y]
+db_initial.data = [0.0*cm,10.0*cm]
+
+# -z face
+[pylithapp.timedependent.bc.z_neg]
+bc_dof = [2]
+label = face_zneg_nofault
+db_initial.label = Dirichlet BC on -z
+
+# ----------------------------------------------------------------------
+# faults
+# ----------------------------------------------------------------------
+[pylithapp.timedependent.interfaces]
+# Change fault to dynamic fault interface.
+fault = pylith.faults.FaultCohesiveDyn
+
+[pylithapp.timedependent.interfaces.fault]
+# The label corresponds to the name of the nodeset in CUBIT.
+label = fault
+
+# Use the static friction model.
+friction = pylith.friction.StaticFriction
+
+# We must define the quadrature information for fault cells.
+# The fault cells are 2D (surface).
+quadrature.cell = pylith.feassemble.FIATLagrange
+quadrature.cell.dimension = 2
+
+# Set static friction model parameters using a uniform DB. Set the
+# static coefficient of friction to 0.6 and cohesion to 0.0 Pa.
+friction.db_properties = spatialdata.spatialdb.UniformDB
+friction.db_properties.label = Static friction
+friction.db_properties.values = [friction-coefficient,cohesion]
+friction.db_properties.data = [0.6,0.0*Pa]
+
+# ----------------------------------------------------------------------
+# output
+# ----------------------------------------------------------------------
+# Give basename for VTK domain output of solution over domain.
+[pylithapp.problem.formulation.output.domain.writer]
+filename = step11/step11.vtk
+
+# Give basename for VTK domain output of solution over ground surface.
+[pylithapp.problem.formulation.output.subdomain]
+# Name of nodeset for ground surface.
+label = face_zpos
+writer.filename = step11/step11-groundsurf.vtk
+
+# Give basename for VTK fault output.
+[pylithapp.problem.interfaces.fault.output]
+writer.filename = step11/step11-fault.vtk
+
+# Give basename for VTK output of upper_crust state variables.
+[pylithapp.timedependent.materials.upper_crust.output]
+# Average values over quadrature points.
+cell_filter = pylith.meshio.CellFilterAvgMesh
+writer.filename = step11/step11-upper_crust.vtk
+
+# Give basename for VTK output of lower_crust state variables.
+[pylithapp.timedependent.materials.lower_crust.output]
+# Average values over quadrature points.
+cell_filter = pylith.meshio.CellFilterAvgMesh
+writer.filename = step11/step11-lower_crust.vtk