plasticity tutorial Koen Wouters | ASTK issue

Hoi Jelle

I changed the commands you indicated and -no suprise- I have the same message you see.
As far as I remember the SIGM_ELNO_DEPL was more or less 'default' in de previous Aster versions. I played a little with the XXXX_ELNO_YYYY and XXXX_NOEU_YYYY fields, but without any success. Maybe we need someone to explain in more detail these fields, that would be very nice anyway.

I will read the docs once again and keep an eye on the CA forum.

added:
It seams that SIGM_ELNO_DEPL and hence SIGM_NOEU_DEPL is for linear analysis only. Because the stresses are derived from the displacement it must assume a linear relation. If I understand the docs correctly (see U2.01.05, $1.6.2.2).

....
SIGM_ELNO_DEPL: Déplacement en élasticité linéaire.


And further:

Préfixe : SIEF_ELGA
Il s'agit des options qui calculent le champ représentatif de l'"état de contrainte" et permettent de poursuivre des calculs (rigidité géométrique, forces nodales, etc..) en des points de Gauss ou en ce qui en tient lieu. Le préfixe de ces options est SIEF, car suivant les éléments, elles calculent des contraintes ou des efforts.

Préfixe : SIEF_ELNO
Il s'agit des options qui calculent le champ représentatif de l'"état de contrainte" à des fins d'exploitation (impression ou post-traitement de visualisation) aux nœuds de la structure.

Préfixe : SIGM_ELNO
Il s'agit des options qui calculent les champs de contraintes quelle que soit la modélisation à des fins d'exploitation (impression ou post-traitement de visualisation) aux nœuds de la structure.

or in Bablenglish:
Prefix: SIEF_ELGA
These are options that calculate the field representative of the "prior restraint" and allow further calculations (geometric stiffness, nodal forces, etc. ..) by Gaussian points in in lieu thereof. The prefix of these options is SIEF, because according to the elements, they compute stress or effort.

Prefix: SIEF_ELNO
These are options that calculate the field representative of the "prior restraint" for operating (printing or post-processing visualization) at the nodes of the structure.


Prefix: SIGM_ELNO
These are options that calculate the stress fields irrespective of patterning for operating (printing or post-processing visualization) at the nodes of the structure.



kind regards - kees<br /><br />Post edited by: Kees Wouters, at: 2010/04/22 14:58

Hoi Jelle

Still going strong: see the update and simplified version www.caelinux.org/wiki/index.php/Contrib:...n_linear_calculation
Still have to figure out the non linear stresses and strains in more details. The linear stresses and strains are given in the previous link.

But for now, if you have any comments, additions, remarks, pls let us know. I simplified the construction such that you can calculate all results by hand (if you are smart enough on the backside of a stamp, but that used to be in the time computers were rare).

If have now an issue regarding post processing in Salome: Salome tends to put very round values for the results (eg 400 MPa for the axial stress and 0.002 for the axial strain). A few days ago I had a work around for it (see linear solution), but in the mean time I forgot. So the last picture is not accurate regarding values for stress and strain, although I am quite sure that CA calculates correctly (of course it does, but: garbage in, garbage out once used to be a saying).

added monday - a few days later:
The geometry and comm files are uploaded.
The non linear stresses and strains have been calculated.

kind regards - kees<br /><br />Post edited by: Kees Wouters, at: 2010/05/03 22:04