Request to include API 579 MPI Omega Method

[Stefano2209]

Dears Thomas,

I would like to know if is possible to include MPC omega method in Mfront, to use that in Code_Aster software.
This method is reported in API 579 - Fitness for service, for creep behavior and damage ratio definition.

More information about is are reported in:

• Development of the MPC Omega Method for Life Assessment in the Creep Range (M.Prager - 1995)
• API 579-1: 2016 - Fitness for service

Feel free to ask me any other information about is.

All the best,
Stefano

[thelfer]

Dear @Stefano2209,

The MFrontGallery project is a meant to show how practically implement a proper way to create portable material data bases for use in safety critical studies. It is the release as an open-source project of the infrastructure that we use internally at CEA and EDF.

For this reason, I think that introducing the MPC omega method in MFrontGallery makes sense.

However, if we were to introduce the MPC omega method`` to the gallery (which will make it available to code_aster` but also many other solvers), we need:

1. The implementation
2. The documentation
3. Unit tests

I can help for Step 1. However, I will need your contributions for Steps 2. and 3.

Let us start with Step 2. You may find an example of a good (unfinished) documentation: https://thelfer.github.io/MFrontGallery/web/SemiImplicitModifiedCamClay_OpenGeoSys2020.html.

You can find another example here: https://thelfer.github.io/tfel/web/Burger_EDF_CIWAP_2021.html

I would ask you if you can summarize the behaviour that you wish to introduce in a document (mostly the typical use case of the behaviour and the constituve equations).

The documentation is written in markdown, but you can send me a LaTeX file so I'll make the conversion.

Best,
Thomas

[thelfer]

Hi,
I just implemented Equation 3-36 of the document that you sent me in private which is meant to cover the third stage of creep.
However, it is quite an unphysical equation as the strain rate does not depend on the von Mises stress.
Let me know if it is a good starting point.
Regards,
Thomas

MPCOmegaViscoplasticBehaviour.zip

[thelfer]

@Stefano2209 Still interested ?

[Stefano2209]

Dear Thomas,

I confirm my interest to this development, but I'm busy in this period.
I'll wrote you details about that as soon as possible.

Thanks again for your support.

All the best,
S

[thelfer]

@Stefano2209 Is this issue still relevant ?