7. G modeling#

7.1. But#

The aim of this test is to validate the use of 3D_SI elements on support mesh HEXA8 with an initial state of displacement and stress and with a loading of applied pressure (PRES_REP/PRES).

7.2. Description#

This modeling is a copy of modeling E in which 3D modeling has been replaced by 3D_SI.

However, for 3D_SI modeling, differences exist between Code_Aster and EPX. This has the effect that the static initial state sent to EPX (with only loading the one already applied) does not give a balanced state in EPX. So the validation is a bit different.

A first calculation is started by activating balancing (EQUI =” OUI “). If at the output of this calculation we find the input displacement and stress values, then the correct consideration of the initial state will be demonstrated for the 3D_SI.

A second calculation is then started without activating balancing (EQUI =” NON “). We visualize the displacement curves of node GRN1 in order to see that the imbalance is quite limited. This calculation makes it possible to qualitatively validate the good consideration of pressure loading and to note that the Code_Aster and EPX models are not too far apart and that it is therefore consistent to use a Code_Aster-EPX chaining with these elements if balancing is activated.

The following figures show the movements of node GRN1 in the 3 directions of space:

_images/1000000000000375000001E5EDE364AF6665D987.png _images/1000000000000336000001ECC4612542FDE69B74.png _images/1000000000000364000001DC8FB83299E7B19835.png

7.3. Principle of validation#

Comparison with the initial state.

7.4. Tested values#

Calculate with EQUI =” OUI “:

Instant Final 4E-3

Node

Component

Reference Type

Reference Value

Tolerance

GRN1

\(\mathit{DX}\)

“AUTRE_ASTER”

“”

-9.42600991306E-06

5E-5

GRN1

\(\mathit{DY}\)

“AUTRE_ASTER”

-6.78188286688E-07

5E-5

GRN1

\(\mathit{DZ}\)

“AUTRE_ASTER”

-6.47139874604E-06

5E-5

Mesh

Component

Point

Reference Type

Reference Value

Tolerance

M93

\(\mathit{SIXX}\)

1

1

“AUTRE_ASTER”

-88191.2920113

5E-5

M93

\(\mathit{SIYY}\)

1

1

“AUTRE_ASTER”

-4298.28256544

1E-4

M93

\(\mathit{SIZZ}\)

1

1

“AUTRE_ASTER”

-89716.486396

5E-5

Calculate with EQUI =” NON “:

Instant Final 2E-2

Node

Component

Reference Type

Reference Value

Tolerance

GRN1

\(\mathit{DX}\)

“AUTRE_ASTER”

-9.42600991306E-06

22%

GRN1

\(\mathit{DY}\)

“AUTRE_ASTER”

-6.78188286688E-07

2, 5%

GRN1

\(\mathit{DZ}\)

“AUTRE_ASTER”

-6.47139874604E-06

42%

Mesh

Component

Point

Reference Type

Reference Value

Tolerance

M93

\(\mathit{SIXX}\)

1

1

“AUTRE_ASTER”

-88191.2920113

0.015%

M93

\(\mathit{SIYY}\)

1

1

“AUTRE_ASTER”

-4298.28256544

100%

M93

\(\mathit{SIZZ}\)

1

1

“AUTRE_ASTER”

-89716.486396

2, 5%