Buckling analysis with STAT_NON_LINE

In Code Aster, a buckling analysis is conducted to use STAT_NON_LINE command.
At this time, I tried following items.

buckling analysis by STAT_NON_LINE
Output a mode at buckling occured
to do a linear buckling analysis eith initial deformation.
And to make comparison between this and above result.

1．ANALYSIS MODEL

Mesh is as below.

DKT element was selected for the analysis to compare the result to another application’s result.

model2 = AFFE_MODELE(AFFE=_F(GROUP_MA=('web', 'top'),
MODELISATION=('DKT', ),
PHENOMENE='MECANIQUE'),
MAILLAGE=mesh2)

Loop of STAT_NON_LINE was broken by a judgement of CRIT_STAB.

ii = 1
FLAG = True

while FLAG:
    resu = STAT_NON_LINE(reuse = resu,
        MODELE=model2,
        CHAM_MATER=fieldma2,
        CARA_ELEM=carac2,
        CONVERGENCE=_F(ITER_GLOB_ELAS=25,ITER_GLOB_MAXI=20),
        CRIT_STAB=_F(CHAR_CRIT=(-1., 0.), ),
        EXCIT=(_F(CHARGE=clim2,TYPE_CHARGE='FIXE_CSTE'),
               _F(CHARGE=charge_2,FONC_MULT=func)),
        COMPORTEMENT=_F(RELATION='ELAS',DEFORMATION='PETIT', ),
        INCREMENT=_F(LIST_INST=list0, NUME_INST_INIT=ii, NUME_INST_FIN=ii+1),
        ETAT_INIT=_F( EVOL_NOLI = resu),
        METHODE='NEWTON',
        NEWTON=_F(MATRICE='TANGENTE',REAC_INCR=1,REAC_ITER=10)
    )

    ccc = resu.LIST_CHAMPS()['MODE_FLAMB']
    if len(ccc) > 0: FLAG=False
    if ii >= nlimit:
        FLAG=False
    else:
        ii = ii+1

And a modification the model to use deformation is as below.

aaa = resu.LIST_VARI_ACCES()['INST']
print aaa
bbb = resu.LIST_CHAMPS()['DEPL']
print bbb
print ccc

defo =CREA_CHAMP(TYPE_CHAM='NOEU_DEPL_R',OPERATION='EXTR',
RESULTAT=resu,NOM_CHAM='DEPL',INST= aaa[ccc[0]],);

mesh2 =MODI_MAILLAGE(reuse =mesh2,
MAILLAGE=mesh2,DEFORME=_F(OPTION='TRAN',DEPL=defo,),);

resuSI = CREA_CHAMP(NOM_CHAM='SIEF_ELGA',
OPERATION='EXTR',RESULTAT=resu,INST= aaa[ccc[0]],TYPE_CHAM='ELGA_SIEF_R')

Smesh = CALC_MATR_ELEM(CARA_ELEM=carac2,
CHAM_MATER=fieldma2,CHARGE=(clim2, charge_2),MODELE=model2,OPTION='RIGI_MECA')

comm file is here。

2．RESULT