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#1 2020-02-14 17:43:53

guillegiraldo
Member
Registered: 2010-05-05
Posts: 27

How to extract Nodal Equivalent Plastic Strain from COQUE_3D

Hi!

My need is to extract Equivalent Plastic Strain at mesh nodes from a non linear static COQUE_3D model.

I know that this value is istored in V1 of the VARI_ELGA field, but I am not able to extract it from a specific thickness level, interpolate to the nodes and project it to the output model, which is the procedure I succesfully use for the case of the Equivalent Strain field.

Could this be achieved in Code Aster (e.g. with PROJ_CHAMP/CALC_CHAMP) or in posprocessing (Paravis)? How to do it?

If someone could point me in the right direction, I would be so grateful.

Best regards,

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#2 2020-02-16 10:17:39

AsterO'dactyle
Administrator
Registered: 2007-11-29
Posts: 301

Re: How to extract Nodal Equivalent Plastic Strain from COQUE_3D

Hello

Use POST_CHAMP to extract values in thickness


Code_Asterの開発者

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#3 2020-02-17 15:05:29

guillegiraldo
Member
Registered: 2010-05-05
Posts: 27

Re: How to extract Nodal Equivalent Plastic Strain from COQUE_3D

Hi, thanks for your response!

I am sorry for not being clear in my first post, maybe thought the problem would be clear and didn't want to make it so long.

I tried to solve the problem with the following workflow:

...
POST_CHAMP(...) # Extract VARI_ELGA at thickness
CALC_CHAMP(...) # Interpolate to nodes (option VARI_ELNO/VARI_NOEU)
PROJ_CHAMP(...) # Sample on linear model without mid-nodes
...

This doesn't work, throwing errors about the field not being present.

I can print the extracted field on the bi-linear mesh, but it is not suitable for the posprocessing I will do. This is why I ask for a method to extract the field on mesh nodes.

By reading the documentation, I came up with a method by computing the EPSI/EPEQ fields but then got EXECUTION_CODE_ASTER_EXIT_6204=0 result. I guess all of those are not implemented for the COQUE_3D elements.

I think this should be possible to be done by Code Aster, it is just that I can't see the way to do it, even after many tries and reading lots of documentation pages.

PS. By the way, I was able to achieve this on Paravis. For the record, attached is an image the filter scenario.

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#4 2020-02-17 20:58:08

AsterO'dactyle
Administrator
Registered: 2007-11-29
Posts: 301

Re: How to extract Nodal Equivalent Plastic Strain from COQUE_3D

OK

It's NEVER a good idea to follow internal state variable at nodes wink


Code_Asterの開発者

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#5 2020-02-17 22:02:24

mf
Member
Registered: 2019-06-18
Posts: 30

Re: How to extract Nodal Equivalent Plastic Strain from COQUE_3D

Good evening,

for what it's worth, with DKT elements and RELATION=VMIS_ISOT_TRAC I am able to extract V1 of VARI_NOEU with:

-) a POST_CHAMP of VARI_ELNO
-) a CALC_CHAMP of VARI_NOEU

Maybe it helps,

Mario.

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#6 2020-02-18 14:15:59

guillegiraldo
Member
Registered: 2010-05-05
Posts: 27

Re: How to extract Nodal Equivalent Plastic Strain from COQUE_3D

AsterO'dactyle wrote:

OK

It's NEVER a good idea to follow internal state variable at nodes wink

Wast thinking about that, and this is why I tried to compute the strain fields at nodes, but also couldn't succeed.

Any more thoughts or experience on this?

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#7 2020-02-18 14:18:31

guillegiraldo
Member
Registered: 2010-05-05
Posts: 27

Re: How to extract Nodal Equivalent Plastic Strain from COQUE_3D

mf wrote:

Good evening,

for what it's worth, with DKT elements and RELATION=VMIS_ISOT_TRAC I am able to extract V1 of VARI_NOEU with:

-) a POST_CHAMP of VARI_ELNO
-) a CALC_CHAMP of VARI_NOEU

Maybe it helps,

Mario.

Thanks Mario! Will have it present when I make use of DKT elements.

Greetings.

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