PyLith Development Plans, Nov 2016

Priorities for! PyLith software development, such as new features and enhancements. This a draft for community comment (Nov 7, 2016).

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.

Version 3.0 (Spring 2017)

– Multiphysics {{expert.png}} 30%

• Implement modular approach for specifying governing equations and computing residuals and Jacobians. {{expert.png}}
• Incompressible elasticity via a pressure field {{intermediate.png}} 20%
• Poroelasticity {{difficult.png}} 5%

– Higher order basis functions {{difficult.png}} 25%

• 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. {{intermediate.png}} 25%

• 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.

– Improve fault formulation for spontaneous rupture {{intermediate.png}} 10%

• Removes inner solve associated with updating Lagrange multipliers. This will significantly accelerate the nonlinear solve.

– Allow full specification of the initial conditions (solution and state variables) {{intermediate.png}} 0%

– Update user manual

• Convert from LyX to LaTeX for ease of maintenance and editing. {{easy.png}} 0%
• Reorganize for multiphysics implementation. {{intermediate.png}} 5%
• Reorganize examples. {{intermediate.png}} 0%
  • Focus on demonstrating the range of physics and features beginning with simple cases and building towards more complex cases.
  • Include ParaView Python scripts for plotting results.
  • Consider moving examples to Jupyter notebooks; export to PDF files for “print” documentation.

Version 3.1 (late 2017)

– GUI interface for specifying simulation parameters {{difficult.png}}

– Add additional multiphysics implementations and rheologies

• Drucker-Prager bulk rheology with relaxation to yield surface {{intermediate.png}}
• Elasticity + heat flow {{difficult.png}}

– Reorganize output for time-dependent Green’s functions and adjoints {{intermediate.png}}

– Multilevel nonlinear solve {{expert.png}}

– Radial basis functions for spatial databases {{intermediate.png}}

– Convert to Python 3 and Pyre 1.0.

Version 4.0 (TBD)

– Earthquake cycle modeling {{difficult.png}}

• 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. {{intermediate.png}}

– Moment tensor point sources via equivalent body forces {{difficult.png}} 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

Major features

• Different meshes for dynamic and quasi-static parts {{expert.png}}
  • 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.

• Use flexibility of multiphysics implementation to support inclusion of data assimilation {{expert.png}}

Minor features

• 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.

difficulty rating system

intermediate

difficult

expert

based on the ski trail rating system

Created on 23 Jan 2021, Last modified on 23 Jan 2021