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#1 2010-12-13 02:15:17

todd_alan_martin
Member
Registered: 2008-03-06
Posts: 131

How to view principal strains/stresess

Hi

I can extract the principal strain/stresses from a solution using

strain=POST_RELEVE_T(ACTION=(_F(OPERATION='EXTRACTION',
                                 INTITULE='Principal Strain',
                                 RESULTAT=res,
                                 NOM_CHAM='EPSI_ELNO_DEPL',
                                 GROUP_NO='Shell',
                                 ELEM_PRINCIPAUX='OUI',),),);

and print them in tabular form via

IMPR_TABLE(TABLE=strain,
           UNITE=38,);

But how do I get these data into gmsh or med format for viewing as a surface contour plot?

Todd.

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#2 2010-12-13 11:21:26

dbpatankar
Member
From: Roorkee, Uttarakhand, India
Registered: 2010-05-22
Posts: 206

Re: How to view principal strains/stresess

Use IMPR_RESU with something like :

IMPR_RESU(FORMAT='MED',
                   UNITE=80,
                   RESU=_F(MAILLAGE=MAIL,
                                  RESULTAT=RESU,
                                  NOM_CHAM=('EPSI_ELNO_DEPL',),
                                  ),
                   );

And add rmed entry to the export file.

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#3 2010-12-13 13:18:36

Archibald Archambaud
Member
From: Clamart, France
Registered: 2007-12-03
Posts: 322

Re: How to view principal strains/stresess

Hi Todd.

You can compute the EQUI_ELNO_EPSI, where you find the component PRIN_1, PRIN_2, PRIN_3 (principal strain). The equivalent for the stress is of course EQUI_ELNO_SIGM.

AA

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#4 2010-12-14 00:51:53

todd_alan_martin
Member
Registered: 2008-03-06
Posts: 131

Re: How to view principal strains/stresess

Thanks Archibald.

I will try that.
Where are these options PRIN_1, PRIN_2, PRIN_3 documented?

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#5 2010-12-14 01:13:53

todd_alan_martin
Member
Registered: 2008-03-06
Posts: 131

Re: How to view principal strains/stresess

Hi Archibald

That doesn't work. I get the following error.

! option  EQUI_ELNO_EPSI  non disponible sur les elements du modele !
   !  pas de champ crea   

I am using 2D elements here, not 3D. Now what???

Last edited by todd_alan_martin (2010-12-14 02:16:53)

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#6 2010-12-14 10:13:01

delmas
Administrator
From: EDF R&D
Registered: 2007-12-12
Posts: 837

Re: How to view principal strains/stresess

Post your .comm file.


Code_Aster release : unstable on (Ubuntu Precise Pangolin 12.04 64 bits) - GNU + Intel

Code_Aster. What else ?

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#7 2010-12-14 11:49:40

rcbsimoes
Member
Registered: 2010-12-09
Posts: 41

Re: How to view principal strains/stresess

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#8 2010-12-14 13:12:30

todd_alan_martin
Member
Registered: 2008-03-06
Posts: 131

Re: How to view principal strains/stresess

Hi Delmas

My comm and med files are attached. Please have a look and advise me.

Thanks,
Todd.


Attachments:
test.tar.gz, Size: 18.32 KiB, Downloads: 402

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#9 2011-05-27 08:33:23

Thomas DE SOZA
Guru
From: EDF
Registered: 2007-11-23
Posts: 3,066

Re: How to view principal strains/stresess

Hi,

Sadly EQUI_ELNO_EPSI (from now on known as EPEQ_ELNO) is not programmed for plates/shells (DKT/DST/COQUE_3D). So this explains the error.
The workaround you suggested in the other post (doing it in GMSH) is one solution. Another would be to use FORMULE + CREA_CHAMP (a great training for CREA_CHAMP use) in Code_Aster to compute by hand the scalar Von Mises strain field.

TdS

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#10 2011-05-30 06:37:21

todd_alan_martin
Member
Registered: 2008-03-06
Posts: 131

Re: How to view principal strains/stresess

Thank Thomas.

That looks like a useful feature.

Todd.

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#11 2012-06-29 23:47:20

toltec
Member
Registered: 2009-01-04
Posts: 94

Re: How to view principal strains/stresess

Hello,


Thomas DE SOZA wrote:

Hi,

Sadly EQUI_ELNO_EPSI (from now on known as EPEQ_ELNO) is not programmed for plates/shells (DKT/DST/COQUE_3D). So this explains the error.
The workaround you suggested in the other post (doing it in GMSH) is one solution. Another would be to use FORMULE + CREA_CHAMP (a great training for CREA_CHAMP use) in Code_Aster to compute by hand the scalar Von Mises strain field.

TdS

Is it still not possible to calculate COQUE_3D principal strains directly in V10.6? If not does anyone perhaps have an example using Thomas's suggestion above? It would be a great help!

I'm doing a STAT_NON_LINE, ELAS analysis and need to determine an effective uniaxial strain. I would therefore like to calculate Mises Stress/Elastic Modulus. This should be sufficient since the material law is elastic.

Thanks and Regards

Gary

Last edited by toltec (2012-06-30 07:45:40)


Ubuntu 12.04
Intel(R) Core(TM)2 Quad CPU    Q9400  @ 2.66GHz

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#12 2012-07-01 23:18:25

Thomas DE SOZA
Guru
From: EDF
Registered: 2007-11-23
Posts: 3,066

Re: How to view principal strains/stresess

If you can afford to use V11 then note that CALC_CHAMP has a neat feature that allows you to compute a field by formula opening a wide range of possibilities. See CHAM_UTIL keyword under CALC_CHAMP.
If you're stuck with V10 then I'm afraid you'll have to do complicated things with CREA_CHAMP if you want to reach your goal.

TdS

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#13 2012-07-02 08:44:53

toltec
Member
Registered: 2009-01-04
Posts: 94

Re: How to view principal strains/stresess

Thanks Thomas. I'm stuck with V10 at the moment and have discovered that I can use Paravis Calculator to do the simple processing that I need. I hope to get onto V11 soon.

Cheers

Gary


Ubuntu 12.04
Intel(R) Core(TM)2 Quad CPU    Q9400  @ 2.66GHz

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