PyLith Development Plans

Version 1.6 [by June training session]

Optimization

• Multiple fields in a single Sieve section 

  At this point, only used for parameters of fault constitutive models.

General

• HDF5 output 

  Output into a single HDF5 file or an HDF5 file with raw binary files for the datasets. Datasets are written using MPI I/O if available in both cases. Add .Xdmf metadata files associated with HDF5 files to permit reading of HDF5 files with ParaView and Visit.

• Uniform global refinement  [98%]

Quasi-static

• Added 2-D plane strain versions of the 3-D generalized Maxwell viscoelastic rheology. 

Dynamic

• Numerical damping via viscosity 

  Added numerical damping via a viscosity parameter that is independent of the bulk constitutive model. The viscosity is applied during the time integration.

Computational science

• None

Version 1.7 (Fall 2011)

Optimization

• Multiple fields in a single Sieve section  [0%]
  • Parameters for bulk constitutive models
  • Parameters and fields related to fault implementation

  Will reduce memory use and provide speedup due to better use of memory cache.

Cleanup

• Separate elastic solution into elasticPrestep() function  [0%]
• Add --initialize_only property to Problem  [0%]

  Permit users to stop simulation before time stepping in order to diagnose parameter settings.

General

• Refactor initial fault tractions  [5%]

  Create Nucleation object with spatial and temporal perturbation of tractions from initial value

Quasi-static

• Add strain hardening/softening to Drucker-Prager elastoplastic models.

Dynamic

• Compute stable time step for explicit time integration  [5%]
• Attenuation via generalized Maxwell model (bulk and shear relaxation)  [50%]

Computational science

• Scalable mesh distribution  [0%]

  Permit running large problems where the mesh cannot fit on a single compute node.

• Accelerate FE integrations using GPUs  [25%]

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

Version 2.0

Optimization

• TBD

Cleanup

• TBD

General

• Moment tensor point sources

  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. 

Quasi-static

• Time-step based on strain rate 
• Pressure field for incompressible elasticity problems 

Dynamic

• TBD

Computational science

• Use KD tree search algorithm to allow output of time histories at an arbitrary location 
• Use interpolated meshes (cells, faces, edges, vertices) to permit higher order basis functions 
• Support for arbitrary number of solution fields (e.g., displacement, temperature, pressure) 
• Adjust integrations to support multi-physics calculations.

Beyond Version 2.0

Optimization

• TBD

Cleanup

• TBD

General

• 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.

Quasi-static

• TBD

Dynamic

• TBD

Computational science

• TBD