MFRONT model repository & visco-hyperelasticity

Nima

Hello all,

Is there any plan for making a model repository for MFRONT so that users can share their models there?

I am looking for an implementation of visco-hyperelastic constitutive equations. Has anyone worked in that direction?

Nima

AsterO'dactyle

Hello,

No "repository" but Mfront is distributed with lot of examples.

If you want, you can give yours new constitutive laws to MFront and don't hesitate to ask questions on forum:

https://sourceforge.net/projects/tfel/

thomas.helfer

Dear user,

Several users requested such a repository. I have begun working on providing documented examples of well-written mechanical behaviours. This is a work in progress, see:

http://tfel.sourceforge.net/gallery.html

Some users are currenly developping hyperviscoelastic behaviours. They will be added to the MFront repository when ready.

Regards,

Helfer Thomas

pierre_j

Hi,

This is a very interesting evolution.

If I may dare (le relou du coin...), do you think you could add tags to the models so as to mention for what kind of material (metallic, plastic, composite, concrete...) / modelling hypothesis (plane strain/stress, linear, non-linear...), the related model has been developped or could be suited?

Myself, I would definitely be interested in an isotropic model suited for chopped fiber reinforced plastic (not necessarily carbon fiber). Do you think some of the existing model could be suited?

I thank you in advance.

Best regards,

Pierre

thomas.helfer

Dear Pierre,

Thank you for your suggestion. I am still searching for a simple way to add such tags in static web pages...

I never treated chopped fiber reinforced plastic, so I can't give you any advice. However, if you find some published mechanical behaviours of interest, do not hesitate to ask if it is simple to implement in MFront.

Regards,

Thomas

bbd

Thomas Helfer has kindly implemented my proposal of visco-hyper law based on Prony Series coupled with Signorini hyper law.

See attached.

Attached file:
HyperViscoelasticity.mfront, 3391kb

thomas.helfer

Hi,

did you have the time to test this implementation in Code_Aster (consistent results, convergence rate, etc... ) ?

Regards,

Thomas

thomas.helfer

Hi,

Concerning the MFRont model repository, I try to provide examples of well written behaviours. For each behaviours, I will also try to propose tutorial-like pages that will explain the implementations details (usage of tensorial objects, special functions of the TFEL library, choice of the algorithms, and so on...)

My first attempt is an hyperelastic behaviour already available in Code_Aster: the Signorini behaviour. You can find the page here:

http://tfel.sourceforge.net/signorini.html

This is still under review, so I would appreciate corrections and feed-backs.

I plan to address next:

1) the Ogden hyperelastic behaviour which will show how we can compute eigenvalues, eigenvectors and isotropic functions of symmetric tensors.

2) hyperviscoelasticity (a very small extension of hyperelasticity, indeed)

3) simple plastic behaviours

If you have particular wishes on behaviours implementation that you would like to see treated, do not hesitate to send a message at [email] tfel-contact.cea.fr[/email].

Regards,

Thomas

pierre_j

thomas.helfer wrote:
Dear Pierre,

Thank you for your suggestion. I am still searching for a simple way to add such tags in static web pages...

I never treated chopped fiber reinforced plastic, so I can't give you any advice. However, if you find some published mechanical behaviours of interest, do not hesitate to ask if it is simple to implement in MFront.

Regards,

Thomas

Hi Thomas,

Thank you very much for your proposal.

I fear it will be kind of fuzzy, but here is an article presenting the approach that is currently under consideration for modelling behavior of Chopped Glass Fiber -SMC (developped by researchers from ENSAM).

If this kind of material is also of interest for you, here is a more recent publication describing a characterization approach that is in-development, but no additional detail is unfortunately given concerning the numerical model.

If you feel some models already available in MFRONT appears suitable, I would be very interested in knowing it.

Best regards,

Pierre

thomas.helfer

Hi Pierre,

From a rapid overview of those papers, I can't figure out a complete set of consistutive equations. However, although some work is required, implementing such behaviours does not seem unreachable at all.

Contact me at [email]tfel-contact@cea.fr[/email] if you can get such equations. Such models can be of interest for us (for describing nuclear fuels).

Regards,

Thomas

pierre_j

Hi Thomas,

Thanks for your proposal. I will try to find a more complete description of the modelling approach, and will keep you informed.

Best regards,

Pierre