SIMO_MIEHE in code_aster 2024

Ava22

Dear code_aster team,

I am working on a crystal plasticity finite element (CPFE) model using the Méric-Cailletaud formulation in mfront. Having moved from code_aster 2021 to 2024, I realized that SIMO_MIEHE deformation is no longer supported in code_aster 2024 with mfront codes. I wonder if there is another alternative to that in order to use a similar formulation (F=Fe*Fp) in v2024, please. The most favorable situation is the existence of an alternative that can still be used with mfront. But if this option is not available, can this formulation still be used in UMAT?

Thank you a lot for your time and support.

Best regards
Ava

AsterO'dactyle

HEllo,

For large strains model:

Using GREEN-LAGRANGE with F gradient as input in MFront => see ssnv187 test-cases and hyper_hill.mfront for instance
Using GDEF_LOG model => write your MFront model in small strains => large strains is automatic. See mfron01h.comm

SIMO_MIEHE is not possible with UMAT.

Ava22

AsterO'dactyle

Thank you so much for your explanation and the provided examples. I will go through them to see how I can revise my codes.

Best regards
Ava