Problem with stresses definition

Hi everyone,

I'm new with code_aster and I'm trying to analyze a single problem consisting in 3 layers of soil (100x100x10 m), so the total height is 30 m. I'm using a simple gravity loading in order to estimate the initial geostatical stresses. As I assigned a RHO=2000 to all three layers, I'm expecting a maximum VERTICAL stress of 600 kPa.

I'm trying to check the results, but I haven't succeed in reading the rmed file in Paravis, as there are not any properties to be activated or to filter (if someone has an idea, I'd appreciate to know what it is). Anyway, I'm reading the rmed file in GMSH, not what I'd like, but at least it does read it! Nevertheless, I'm facing a problem because the value of stress (actually only one stress is displayed, and I have no idea what it is) shows a maximum value of 780 kPa, which doesn't agree with the expected value.

At first I though that it would mean a calculation error. Later, I thought that there was a problem of visualization in GMSH, because I was using quadratic elements (I couldn't fix it with "adapt visualization grid"). Therefore, I started using linear elements, but the problem remains. Additionally, as I said, I can make the file to be read by ParaVis, I can't compare it.

After all that now I think that actually what it's being displayed is some kind of equivalent stress, that takes all component of the stress tensor into account. Am I right? If so, how can I get the stress tensor to be separated into its six components?

Here is the code for recording results:

RESU=CALC_CHAMP(reuse=RESU,

RESULTAT=RESU,

CONTRAINTE=('SIGM_ELNO','SIGM_NOEU'),

CRITERES=('SIEQ_ELNO','SIEQ_NOEU',),);



IMPR_RESU(FORMAT='MED',

UNITE=80,

RESU=_F(RESULTAT=RESU,

NOM_CHAM=('SIGM_NOEU','SIEQ_NOEU','DEPL',),),);

This is what EFICAS wrote, and I just let it so, because I must admit my ignorance about what is being passed. I also post in the salome forum about the meaning of those values, because today the code_aster forum is closed. If someone can also take a look to that post and give me some hint here, I'd be more than thankful:

www.salome-platform.org/forum/forum_10/645511241

Cheers,

Ferney

Hi,

I found a way how to check it . In this thread webcache.googleusercontent.com/search?q=...ewtopic.php?id=16674 J.P Aubry gives the advice to plot in GMSH like this:


First of all it is a good idea to go in Tools -> Options-> Mesh Visibility

To view one specific component in an ELNO type field the following sequence must be followed :

in the Visibility tab pull the lower left list to Force scalar;
in the box immediately to the right type the field Id (for a SIPO_ELNO field 0 is for SN, 4 is for SMFY for example);
in the General tab pull the list Range mode to Custom;
and push the Min and Max buttons to refresh the display the proper component values.

We should not forget the Min and Max buttons to be sure than the displayed field and the scalar bar are matched.

and advices to plot in the .RESU file some values, such he suggests in his great book. There he suggests using SIPO_ELNO, but that gave me error and at the end I had to use SIGM_ELNO as follows:

IMPR_RESU ( MODELE=todo,
FORMAT='RESULTAT' ,
RESU=(_F(RESULTAT=RESU,
NOM_CHAM='SIGM_ELNO' ,
NOM_CMP=('SIXX' ,'SIYY','SIZZ',) ,
GROUP_MA=('TOUT',) ,
FORMAT_R='1PE12.3' ,
VALE_MAX='OUI' ,
VALE_MIN='OUI' ,
INST=10,
),
),
);

And after using again quadratic elements I got:

LA VALEUR MAXIMALE DE SIXX EST 9.919E-09 EN 1 MAILLE(S) : M14125
LA VALEUR MAXIMALE DE SIYY EST 7.543E-09 EN 1 MAILLE(S) : M9507
LA VALEUR MAXIMALE DE SIZZ EST 1.260E-08 EN 1 MAILLE(S) : M9647
LA VALEUR MINIMALE DE SIXX EST -2.571E+05 EN 1 MAILLE(S) : M6363
LA VALEUR MINIMALE DE SIYY EST -2.571E+05 EN 1 MAILLE(S) : M6146
LA VALEUR MINIMALE DE SIZZ EST -6.000E+05 EN 1 MAILLE(S) : M7701

Values that validate that the model is running as expected.

I still have no clue why the rmed file is not being read in ParaVis... any idea?

Thx again, Ferney