geodynamics/pylith v3.0.0

Version 3.0.0 includes major changes to the underlying finite-element formulation and implementation in order to support a more flexible specification of the governing equations and higher order basis functions. These changes affect how simulations are defined. Parameter files for previous versions will need to be updated; the changes are too complex for a simple translation table. Some features present in v2.2.2, such as spontaneous rupture and finite strain, have not yet been implemented in the new formulation.

Features

• Multiphysics
  • Elasticity for linear isotropic materials and linear Maxwell, generalized Maxwell, and power law viscoelastic models
  • Incompressible elasticity for linear isotropic materials
  • Prescribed slip for quasistatic and dynamic simulations
• Higher order basis functions Allow user to select order of basis functions independent of the mesh (which defines the geometry). This permits higher resolution for a given mesh.
• Switch to using PETSc time-stepping (TS) algorithms Replace simple Python-based time-stepping implementations with PETSc time-stepping algorithms that provide support for higher order discretization in time and real adaptive time stepping.
• Static Green's functions with user-specified discretization of fault slip impulses
• Import finite-element meshes from Cubit (Exodus II), Gmsh, and LaGriT
• Modular approach for initial conditions
• Output of subfields with user-defined basis order
• Simulation metadata with command line utility for searching metadata
• Convert to Python 3
• Convert LaTeX documentation to Sphinx + MyST
• Testing with the Method of Manufactured Solutions
• Automatically assign label value for fault cohesive cells (id setting is obsolete).
• Use description for descriptive labels and label and label_value for tagging entities. PyLith's use oflabel and label_value now corresponds to PETSc labels and label values.

Known issues

• Running in parallel has a few minor bugs due to communication mismatches and over-aggressive error checking. We will be fixing these in the next week.

Deprecated features

• We plan to discontinue support for reading LaGriT mesh files in version 3.2. \ Gmsh provides an open-source alternative with a graphical user interface.

Contributors

• Brad Aagaard
• Matthew Knepley
• Charles Williams
• Robert Walker
• Chris Mills
• Shengduo Liu
• Thea Ragon
• Alex Berne
• Jed Brown
• Rey Koki
• Kali Allison
• Lorraine Hwang