4. B modeling#
4.1. Characteristics of modeling#
Figure 4.1-1: Modeling B mesh
Boundary conditions:
: label: EQ-None
mathit {N1} mathit {N2}
Table 4.1-1: Boundary conditions for B modeling
Charging:
Traction on the face \(\mathrm{[}\mathrm{3,}4\mathrm{]}\) (mesh SEG2)
The total number of increments is 20 (20 increments between \(t\mathrm{=}\mathrm{0s}\) and \(\mathrm{2s}\))
Convergence is achieved if residue RESI_GLOB_RELA is less than or equal to 10—6.
4.2. Characteristics of the mesh#
Number of knots: 4
Number of meshes: 2
1 QUAD4
1 SEG2
4.3. Tested sizes and results#
Identification |
Reference |
Tolerance |
||
SIMO_MIEHE |
GDEF_LOG |
HPP |
||
\(t\mathrm{=}2\) Displacement \(\mathit{DX}\) (\(\mathit{N8}\)) |
290 |
290 |
290 |
1.00% |
\(t\mathrm{=}2\) Constraints \(\mathit{SIGXX}\) (\(\mathit{PG1}\)) |
1495 |
1495 |
1570 |
1.00% |
|
0.2475 |
0.2475 |
0.282 |
1.50% |
\(t\mathrm{=}2\) ENER_ELAS, TOTALE |
2.82E+009 |
2.81 E9 |
3.08 E9 |
5.00% |
Table 4.3-1: Model B results
4.4. GDEF_LOG with ETAT_INIT#
To impose an initial stress field in large deformations with the GDEF_LOG formalism, the user must give as input the stress tensor defined in the \(T\) logarithmic space (and not that of Cauchy \(\sigma\)). Since the components of the latter are stored as internal variables, it is necessary to use the operands VARI and DEPL of the keyword factor ETAT_INIT of the command STAT_NON_LINE as indicated below (these fields can for example be obtained by the command CREA_CHAMP).
We get the internal variables field (to obtain \(T\)) and also the corresponding displacement field:
VAR_LOG1 = CREA_CHAMP (INFO =2,
TYPE_CHAM =” ELGA_VARI_R “,
OPERATION =” EXTR “,
RESULTAT = LOG1,
NOM_CHAM =” VARI_ELGA “,
INST =1.0,);
DEP_LOG1 = CREA_CHAMP (INFO =2,
TYPE_CHAM =” NOEU_DEPL_R “,
OPERATION =” EXTR “,
RESULTAT = LOG1,
NOM_CHAM =” DEPL “,
INST =1.0,);
then we enter in STAT_NON_LINE, the initial stress state:
ETAT_INIT =_F (VARI = VAR_LOG1,
DEPL = DEP_LOG1).