PyLith v4.2.1

Some features present in v2.2.2, such as spontaneous rupture and finite strain, have not yet been implemented in the new multiphysics formulation used in v3.0.0 and later.

Changed

• Update PETSc to v3.23.5
• Use the VTU (XML) format for VTK files instead of the legacy ASCII format (required for PETSc v3.23.5).

Added

• Improved documentation for pylith_eqinfo and illustrate use in examples/strikdslip-2d, examples/crustal-strikeslip-2d, and examples/crustal-strikeslip-3d.
• Improved the organization of the governing equations section and added documentation for poroelasticity with prescribed fault slip, including governing equations and default PETSc solver settings. Also added a full-scale test.

Fixed

• Account for processes without cells in initial condition patch when verifying configuration.
• Avoid divide by zero for KinSrcRamp when final slip is zero.
• Remove solid_bulk_modulus as a spatial database field for poroelasticity; compute it from the other fields.
• Fixed typos in setting up gravity with poroelasticity.
• Update default solver settings for poroelasticity and faults.
• Fix pythia import in pylith_eqinfo.

Known issues

• The new default preconditioner for simulations using elasticity and faults can cause convergence issues when running in parallel in which fault faces lie on the boundaries between processors. The workaround is to use the previous preconditioner provided in share/settings/solver_fault_fieldsplit.cfg.
• The default PETSc options provide a computationally expensive preconditioner when solving incompressible elasticity problems. We expect to have a more optimal preconditioner in v5.0.0.

Contributors

• Brad Aagaard ORCID iD 0000-0002-8795-9833
• Matthew Knepley ORCID iD 0000-0002-2292-0735
• Charles Williams ORCID iD 0000-0001-7435-9196