PyLith Development Plans

Version 1.8.1 (by mid-late April)

Bug fixes

• Improve solver for rate-state friction and explicit time stepping.  [50%]
• Remove duplicate impulses in parallel Green's function simulations. 

Version 2.0 (by June workshop)

Computational science

• Replace Sieve implementation of finite-element data structures with more efficient DMPlex implementation.  [80%]

  DMPlex implementation is better integrated within PETSc. Smaller memory usage. Developed to support multiphysics and higher order discretizations.

• Higher order basis functions  [0%]

  Allow user to select order of basis functions independent of the mesh (which defines the geometry). This permits higher resolution for a given mesh.

Version 2.1 (Fall or Winter 2013)

Major features

• Earthquake cycle modeling 

  Same mesh for dynamic and quasi-static parts (dynamic -> quasi-static, quasi-static -> dynamic, complete cycle)

Minor features

• Create strain hardening/softening 2-D and 3-D Drucker-Prager elastoplastic models. 
• Attenuation via generalized Maxwell model (bulk and shear relaxation)  [50%]
• Moment tensor point sources via equivalent body forces  [5%]

  Moment tensor point sources provide a mesh independent deformation source that is better suited for Green's function calculations than slip on a fault surface via cohesive cells.

Candidate Features for Version 2.2 (Spring 2014)

Major features

• Multiphysics
  1. Incompressible elasticity via a pressure field 
  2. Elasticity + heat flow 
  3. Elasticity + fluid flow 

Minor features

• Time-step based on strain rate 
• Accelerate FE integrations using GPUs  [5%]

  Will provide significant speedup to simulations run by many users because most are running on desktop machines that have GPUs.

Features for Future Releases

Major features

• Earthquake Cycle Modeling
  1. Different meshes for dynamic and quasi-static parts 

     Requires interpolation of fields between different meshes/discretizations and may require extrapolation of solutions when quasi-static problems span a larger domain than the dynamic problems.

Minor features

• Use KD tree search algorithm to allow output of time histories at an arbitrary location 
• Combined prescribed slip / spontaneous rupture fault condition 

  Use fault constitutive model to control slip on fault except during episodes of prescribed slip. Need some way to describe when to turn on/off prescribed slip.

• Use threading to accelerate integrations on multi-core machines.