how does OBSERVATION work?

jacob

Hello,
how does OBSERVATION work? If I define it, it does not print anything like SUIVI_DDL.

meysam

SUIVI_DDL:

writes the information at "all" newton-iterations.
prints to the convergence table

OBSERVATION:

allows to specify different write-intervals from ARCHIVAGE
Works with node groups as input
Creates by default a table that needs to be extracted (RECU_TABLE) and printed (IMPR_TABLE)

meysam

See for instance test ssna121a.comm for the ARCHIVAGE usage or ssnp170l.comm for printing the table results

RES = STAT_NON_LINE(
    INFO=1,
    AFFICHAGE=_F(INFO_RESIDU="OUI"),
    MODELE=MODI,
    CHAM_MATER=AFFE,
    EXCIT=(
        _F(CHARGE=CHAR1, FONC_MULT=RAMPE),
        _F(
            CHARGE=CHAR2,
            FONC_MULT=RAMPE,
            # TYPE_CHARGE='SUIV',
        ),
    ),
    CONTACT=DEFICO,
    NEWTON=_F(MATRICE="TANGENTE", REAC_ITER=1),
    COMPORTEMENT=_F(RELATION="ELAS", DEFORMATION="PETIT", TOUT="OUI"),
    INCREMENT=_F(LIST_INST=LINST),
    SOLVEUR=_F(ELIM_LAGR="NON", METHODE="MUMPS", RESI_RELA=1.0e-6, PCENT_PIVOT=30),
    OBSERVATION=(
        _F(
            OBSE_ETAT_INIT="NON",
            NOM_CMP=("PRES", "JEU", "CONT", "COEFSURF", "PRESCOOR"),
            NOM_CHAM="CONT_ELEM",
            GROUP_MA="C1527",
            INST=(1.0),
            EVAL_CHAM="VALE",
        ),
    ),
    CONVERGENCE=_F(RESI_GLOB_RELA=1.0e-6, ITER_GLOB_MAXI=50),
)

IMPR_RESU(
    FORMAT="RESULTAT",
    RESU=_F(RESULTAT=RES, NOM_CHAM=("SIEF_ELGA", "CONT_ELEM"), INST=1.0, GROUP_MA=("C1527")),
)

TAB = RECU_TABLE(CO=RES, NOM_TABLE="OBSERVATION")
print(TAB.EXTR_TABLE())

IMPR_TABLE(TABLE=TAB)

jacob

But if it is printed only AFTER solving, then what is difference between using POST_RELEVE_T?

meysam

The main difference from my POV is the granularity of the data. That is you do not need to store all the results just because you are interested at results of a few points with finer resolution. In other words you ca save on disk space

jacob

but the same does POST_RELEVE_T

meysam

With OBSERVATION you can have different time sampling rates:

LIST_INST: Specify exact time instants
PAS_OBSE: Sample every N time steps
INST: Specific time values
So you can have different output freq as compared to ARCHIVAGE

I do not think POST_RELEV_T can do that. If it can, could you please give an example on how