Currently, following Meyer and Ekre (2023), the interface assumes that the dsdp field in MaterialDerivatives is calculated neglecting the influence of dⁿsdp, and this should be added in derivatives working with stress iterations. This is not documented, and is not logical, and should be changed such that the MaterialDerivatives contain this history dependence.
This will require changes to,
- All material implementations (adding the term
ds/dⁿs * dⁿs/dp to the dsdp calculation)
- MMB: Need interface for
reset_derivatives!(::MaterialDerivatives, ::AbstractMaterial) (defaults to setting all to zero, but can be overloaded in case initial state variables depend on material parameters) and default reset_derivatives!(::MaterialDerivatives, previous::MaterialDerivatives) to transfer dsdp if the simulation continues from a previous simulation.
- MatModFit: Need to reset
MaterialDerivatives at beginning of new simulations
- MatModFit/MMB:
StressIterDerivatives must be updated removing the term ds/dⁿs * dⁿs/dp. Potentially this should be moved to MMB to better handle different stress states.
Currently, following Meyer and Ekre (2023), the interface assumes that the dsdp field in
MaterialDerivativesis calculated neglecting the influence ofdⁿsdp, and this should be added in derivatives working with stress iterations. This is not documented, and is not logical, and should be changed such that theMaterialDerivativescontain this history dependence.This will require changes to,
ds/dⁿs * dⁿs/dpto the dsdp calculation)reset_derivatives!(::MaterialDerivatives, ::AbstractMaterial)(defaults to setting all to zero, but can be overloaded in case initial state variables depend on material parameters) and defaultreset_derivatives!(::MaterialDerivatives, previous::MaterialDerivatives)to transfer dsdp if the simulation continues from a previous simulation.MaterialDerivativesat beginning of new simulationsStressIterDerivativesmust be updated removing the termds/dⁿs * dⁿs/dp. Potentially this should be moved to MMB to better handle different stress states.