Step 3: Multiple Earthquake Ruptures and Velocity Boundary Conditions#
Features
Triangular cells
pylith.meshio.MeshIOPetsc
pylith.problems.TimeDependent
pylith.materials.Elasticity
pylith.materials.IsotropicLinearElasticity
pylith.faults.FaultCohesiveKin
pylith.faults.KinSrcStep
field split preconditioner
Schur complement preconditioner
pylith.bc.DirichletTimeDependent
spatialdata.spatialdb.UniformDB
pylith.meshio.OutputSolnBoundary
pylith.meshio.DataWriterHDF5
Quasi-static simulation
spatialdata.spatialdb.SimpleDB
Simulation parameters#
This example involves a quasistatic simulation that solves for the deformation from velocity boundary conditions and multiple earthquake ruptures on the fault.
The velocity boundary conditions match those in Step 2.
We prescribe the first earthquake rupture to occur at 100 years with 1 meter of right-lateral slip and the second earthquake rupture to occur at 200 years with 3 meters of right-lateral slip.
Fig. 58 shows the boundary conditions on the domain.
The parameters specific to this example are in step03_multislip_velbc.cfg
.
[pylithapp.problem.interfaces.fault]
eq_ruptures = [one, two]
[pylithapp.problem.interfaces.fault.eq_ruptures.one]
db_auxiliary_field = spatialdata.spatialdb.UniformDB
db_auxiliary_field.description = Fault rupture one
db_auxiliary_field.values = [initiation_time, final_slip_left_lateral, final_slip_opening]
db_auxiliary_field.data = [100.0*year, -1.0*m, 0.0*m]
[pylithapp.problem.interfaces.fault.eq_ruptures.two]
db_auxiliary_field = spatialdata.spatialdb.UniformDB
db_auxiliary_field.description = Fault rupture two
db_auxiliary_field.values = [initiation_time, final_slip_left_lateral, final_slip_opening]
db_auxiliary_field.data = [200.0*year, -3.0*m, 0.0*m]
Running the simulation#
$ pylith step03_multislip_velbc.cfg
# The output should look something like the following.
>> /software/unix/py39-venv/pylith-debug/lib/python3.9/site-packages/pylith/meshio/MeshIOObj.py:44:read
-- meshiopetsc(info)
-- Reading finite-element mesh
>> /src/cig/pylith/libsrc/pylith/meshio/MeshIO.cc:94:void pylith::meshio::MeshIO::read(topology::Mesh *)
-- meshiopetsc(info)
-- Component 'reader': Domain bounding box:
(-50000, 50000)
(-75000, 75000)
# -- many lines omitted --
25 TS dt 0.1 time 2.4
0 SNES Function norm 1.078084164687e-03
Linear solve converged due to CONVERGED_ATOL iterations 29
1 SNES Function norm 2.500834427760e-12
Nonlinear solve converged due to CONVERGED_FNORM_ABS iterations 1
26 TS dt 0.1 time 2.5
>> /software/unix/py39-venv/pylith-debug/lib/python3.9/site-packages/pylith/problems/Problem.py:201:finalize
-- timedependent(info)
-- Finalizing problem.
The beginning of the output written to the terminal is identical to that from Step 1. At the end of the output, we see that the simulation advanced the solution 26 time steps. Remember that the PETSc TS monitor shows the nondimensionalized time and time step values.
Visualizing the results#
In Fig. 59 we use ParaView to visualize the x displacement field using the viz/plot_dispwarp.py
Python script.
As in Step 2 we override the default name of the simulation file with the name of the current simulation.
>>> SIM = "step03_multislip_velbc"
Next we run the viz/plot_dispwarp.py
Python script as described in ParaView Python Scripts.
Tip
You can use the “play” button to animate the solution in time.