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#1 2021-11-22 16:03:05

stefano89
Member
Registered: 2018-04-16
Posts: 42

Gasket Material Law

Dear Code_Aster users,

I would like to know if there's a pre-defined material law for gasket material.
In particular, I'm interest to behavior law reported in attached figure (from Nastran User Manual).
Then, different behavior need to be defined in load and unload phases.

All the best,
Stefano


Attachments:
Gasket.PNG, Size: 49.35 KiB, Downloads: 111

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#2 2021-11-22 18:21:35

miib
Member
From: La Capanna Dello Zio Tom
Registered: 2021-03-23
Posts: 199

Re: Gasket Material Law

is this of your interest ???

3.8 Keyword factor ELAS_HYPER
Definition of the characteristics very-rubber bands of the type Signorini [R5.03.19]. Constraints of Piola
Kirchhoff S are connected to the deformations of Green-Lagrange by

link:

code-aster.org/V2/doc/v13/en/man_u/u4/u4.43.01.pdf

:-)


I ever used code_aster for study.
Code_Aster ??? is the Novacula Occami of the FEM world.
“Non è bene cercare di fermare il progresso della conoscenza. L'ignoranza non è mai meglio della conoscenza.” Enrico Fermi.

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#3 2021-11-22 21:02:56

stefano89
Member
Registered: 2018-04-16
Posts: 42

Re: Gasket Material Law

Dear,

thank you very much for your answer.
The point is different, because as you could see from the previously attached figure, I have a different unload curve.
This behaviour is typical for gasket material, as per EN 13155 for example.

So I could use the ELAS_HYPER for first gasket compression condition, but during gasket unloading (for example during internal pressure application) I need to define different relation.

There's a predefined material law that could perform this?

All the best
S

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#4 2021-11-22 22:43:47

miib
Member
From: La Capanna Dello Zio Tom
Registered: 2021-03-23
Posts: 199

Re: Gasket Material Law

PRE_SIGM ???
link:
code-aster.org/V2/doc/v14/en/man_u/u4/u4.44.01.pdf

:-)

or a multi stage :

first : all blocked and a PRE_SIGM, compuation
second : same material ,initial condition bring from the end condition of the first stage

iterating

i never tried it, i'm thinking with you about.


Attachments:
pre_sigm.png, Size: 190.58 KiB, Downloads: 99

I ever used code_aster for study.
Code_Aster ??? is the Novacula Occami of the FEM world.
“Non è bene cercare di fermare il progresso della conoscenza. L'ignoranza non è mai meglio della conoscenza.” Enrico Fermi.

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#5 2021-11-25 11:41:36

miib
Member
From: La Capanna Dello Zio Tom
Registered: 2021-03-23
Posts: 199

Re: Gasket Material Law

attached an example of:

hyperelastic material with and without pre load ( in sigma epsilon)

tell me if it is of your interest. :-)


Attachments:
POSTED_PRE_SIGMA.zip, Size: 246.52 KiB, Downloads: 94

I ever used code_aster for study.
Code_Aster ??? is the Novacula Occami of the FEM world.
“Non è bene cercare di fermare il progresso della conoscenza. L'ignoranza non è mai meglio della conoscenza.” Enrico Fermi.

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#6 2021-11-25 11:44:05

miib
Member
From: La Capanna Dello Zio Tom
Registered: 2021-03-23
Posts: 199

Re: Gasket Material Law

here the mesh :-)


Attachments:
MESH.zip, Size: 42.09 KiB, Downloads: 95

I ever used code_aster for study.
Code_Aster ??? is the Novacula Occami of the FEM world.
“Non è bene cercare di fermare il progresso della conoscenza. L'ignoranza non è mai meglio della conoscenza.” Enrico Fermi.

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