PyLith Development Plans, Mar 2015
Priorities for PyLith software development, such as new features and enhancements. This a draft for community comment (Mar 6, 2015).
This plan attempts to balance meeting short-term objectives of delivering high priority, new features and meeting long-term objectives of extending the code to solve a broader range of scientific problems.
Current development has slowed because Brad Aagaard (who is not funded by CIG) is unable to devote much time to PyLith development as a result of a substantial increase of other obligations.
Version 2.2 (Jun 2015)
- Improve fault formulation for spontaneous rupture 10%
- Removes inner solve associated with updating Lagrange multipliers. This will significantly accelerate the nonlinear solve.
- Add viscoelastic Drucker-Prager bulk rheology
Version 2.3 (late 2015)
- 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.
- Reorganize top-level code to conform to layout needed for multiphysics 0%
- Setup modular approach for specifying governing equations and computing residuals and Jacobians.
- Reorganize top-level code to allow different startup cases 0%
- Elastic prestep
- User-specified initial solution
- Checkpoint via special spatial database?
- Multilevel nonlinear solve
- Radial basis functions for spatial databases 0%
Version 3.0 (Spring 2016)
- GUI interface for specifying parameters
- Switch to using PETSc time-stepping (TS) algorithms. 0%
- 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.
- Begin implementation of data assimilation capabilities via adjoint equation.
Version 3.1 (Fall 2016)
- Earthquake cycle modeling
- Same mesh for dynamic and quasi-static parts (dynamic -> quasi-static, quasi-static -> dynamic, complete cycle)
- Create strain hardening/softening 2-D and 3-D Drucker-Prager elastoplastic models.
- 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.
Features for Future Releases
- Earthquake Cycle Modeling
- Data assimilation
- 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.
difficulty rating system
based on the ski trail rating system