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#1 2014-12-12 13:17:37

rcrozier
Member
Registered: 2014-09-18
Posts: 11

SIGM_NOEU vs SIEQ_NOEU, what am I interested in?

I have outputted the calculated fields SIGM_NOEU and SIEQ_NOEU in my med file, but could someone explain exact what each is, and which I should be using to assess the maximum stresses in my shape?

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#2 2014-12-12 13:51:26

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

Re: SIGM_NOEU vs SIEQ_NOEU, what am I interested in?

SIGM_NOEU is the stress field averaged on nodes from values on nodes per elements.
SIEQ_NOEU is the equivalent stress field (contains some criterion like Von-Mises stress or Tresca stress) averaged on nodes from values on nodes per elements.

If you need to assess the maximum stresses in your shape you should consider SIGM_ELGA (the stress field on Gauss point) because this is the true computed values. SIGM_ELNO is located on nodes per element obtained with extrapolation from Gauss point values.

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

Code_Aster. What else ?

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#3 2014-12-12 15:25:06

rcrozier
Member
Registered: 2014-09-18
Posts: 11

Re: SIGM_NOEU vs SIEQ_NOEU, what am I interested in?

Thanks for the explanation and advice.

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#4 2014-12-15 11:09:21

rcrozier
Member
Registered: 2014-09-18
Posts: 11

Re: SIGM_NOEU vs SIEQ_NOEU, what am I interested in?

I have managed to print out SIGM_ELGA in a table in my resu file, but am struggling to view SIGM_ELGA, in Salome Meca ParaVis. My model is 3D made up of tetrahedrons. Here is one attempt:

# Post-Processing
results = CALC_CHAMP(reuse=results,
RESULTAT=results,
CONTRAINTE=('SIGM_ELGA', 'SIGM_ELNO','SIGM_NOEU'),
CRITERES=('SIEQ_ELNO','SIEQ_NOEU',),
);

# Create the med file for salome
IMPR_RESU(FORMAT='MED',
#UNITE=80,
INFO=2,
RESU=(
_F(RESULTAT=results,
NOM_CHAM=('SIGM_ELGA', 'SIGM_NOEU','SIEQ_NOEU','DEPL',),
),
),
);

When I do this, I get the option to import 'results_SIGM_ELGA' in the Representation in the properties area (unlike the other things, such as results_SIGM_ELNO it has a little 'sum' symbol here beside it). However, I would like to display the stress field by using 'Colour By' in the display tab, but the only related thing that appears is something called 'ELGA@0' which seems to display something more like the the mesh element indices, rather than the stress.

How can I display the stresses in ParaVis?

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#5 2014-12-15 14:37:50

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,622

Re: SIGM_NOEU vs SIEQ_NOEU, what am I interested in?

hello

as pointed out above by delmas S***_ELGA is the true precise result  and S***_ELNO is an averaged value at the nodes
but S***_ELGA which is not averaged cannot be plotted by a viewer in a human readable view, it usually shows as sprites, and i do not know how to do it in ParaVis, if it is possible
S***_ELNO is the most practical one to plot
you will find instruction how to plot this in ParaVis in chapter 8.4 of my book
http://framabook.org/14-beginning-with-code_aster/

jean pierre aubry

consider reading my book
freely available here https://framabook.org/beginning-with-code_aster/

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#6 2014-12-16 09:06:21

rcrozier
Member
Registered: 2014-09-18
Posts: 11

Re: SIGM_NOEU vs SIEQ_NOEU, what am I interested in?

Hi jean pierre,

Thanks for explaining that for me, I have also been using your book for some time now to get started. It's been extremely helpful, so thanks for that too!

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#7 2014-12-16 09:16:12

jeanpierreaubry
Guru
From: nantes (france)
Registered: 2009-03-12
Posts: 3,622

Re: SIGM_NOEU vs SIEQ_NOEU, what am I interested in?

thanks

i discovered that going in
Filters > Integrations Points > ELNO Mesh
from the ELGA view produces a new view that can be colorized
in did not check in the details if the values are OK

sprites can be colorized as well in this view
but do not use a Texture on the sprite view it may become meaningless

in general do not use Texture or light in Post pro views

consider reading my book
freely available here https://framabook.org/beginning-with-code_aster/

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