Code_Aster ®
Version
7.4
Titrate:
SSNV144 ­ Coude in inflection in great displacements

Date
:

07/11/05
Author (S):
J.M. PROIX, Key P. MASSIN
:
V6.04.144-A Page:
1/6

Organization (S): EDF-R & D/AMA
Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
V6.04.144 document
SSNV144 - Coude in inflection into large
displacements

Summary:

This test validates the modeling of the phenomena of inflection of hull in great displacements in the field
rubber band or elastoplastic: an elbow of piping, prolonged by right pipes is subjected to an inflection
in its plan. Piping is thick (of size similar to the elbows of the primary education circuits).
reference solution is numerical: it is obtained with Code_Aster using a grid 3D of the elbow.

Modeling is carried out with elements COQUE_3D in great displacements or elastoplasticity.

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/05/005/A

Code_Aster ®
Version
7.4
Titrate:
SSNV144 ­ Coude in inflection in great displacements

Date
:

07/11/05
Author (S):
J.M. PROIX, Key P. MASSIN
:
V6.04.144-A Page:
2/6

1
Problem of reference

The elbow has as a radius of curvature: Rc = 1.25m


With
L
B
Rc
L
Y
Mz
C
D
X



The tubular section has for average radius R = 395.5mm and a thickness E = 77mm.

1.1
Properties of materials

The material is elastoplastic with isotropic linear work hardening.
E = 2.E11 Pa
= 0.3
Elastic limit SIGY = 200.106 Pa
Modulate work hardening D_SIGM_EPSI = 2.1010 Pa

1.2
Boundary conditions and loadings

Embedding of A (corresponding to the section of named piping CERCLE1).

Moment MZ imposed in D (correspondent with CERLCE2) growing until:

Increment 1
Mz = 308670215.2 Nm

In the case of calculation into large displacement, Mz is reached in 10 equal increments

1.3 Conditions
initial

Without object.

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/05/005/A

Code_Aster ®
Version
7.4
Titrate:
SSNV144 ­ Coude in inflection in great displacements

Date
:

07/11/05
Author (S):
J.M. PROIX, Key P. MASSIN
:
V6.04.144-A Page:
3/6

2
Reference solution

2.1
Method of calculation used for the reference solution

In linear elasticity, cf [V6.02.117] one carries out a comparison with other numerical results
obtained with Code_Aster on a grid 3D of the elbow and right parts, connected at the ends to
right beams. This grid 3D comprises 1024 meshs HEXA20. A modeling COQUE_3D
give close results.

2.2
Results of reference

For one moment applied Mz in D, displacement DY of the same point D is worth:

Moment
Dy not D (m) (3D)
Dy not D (m) (COQUE_3D)
3.08670D+08 1.09349D02
1.08875D02

2.3
Uncertainty on the solution

Owing to the fact that the reference solution is numerical, one can evaluate the precision according to [§2.2] to 2% by
comparison of the 3D solutions and COQUE_3D.

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/05/005/A

Code_Aster ®
Version
7.4
Titrate:
SSNV144 ­ Coude in inflection in great displacements

Date
:

07/11/05
Author (S):
J.M. PROIX, Key P. MASSIN
:
V6.04.144-A Page:
4/6

3 Modeling
With

3.1
Characteristics of modeling

COQUE_3D


3.2
Characteristics of the grid

A number of nodes: 1480
A number of meshs and type: 360 QUAD9

3.3
Functionalities tested

Commands Options


“MECHANICAL” AFFE_MODELE
“COQUE_3D”

DEFI_MATERIAU “ECRO_LINE”

DEFI_MATERIAU “ELAS”


AFFE_CARA_ELEM HULL


STAT_NON_LINE VMIS_ISOT_LINE


STAT_NON_LINE DEFORMATION GREEN_GR

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/05/005/A

Code_Aster ®
Version
7.4
Titrate:
SSNV144 ­ Coude in inflection in great displacements

Date
:

07/11/05
Author (S):
J.M. PROIX, Key P. MASSIN
:
V6.04.144-A Page:
5/6

4
Results of modeling A

4.1 Values
tested

To compare the results of the linear elastic design (MECA_STATIQUE) with the solution of
reference, one compares displacements of 4 nodes of the section of the tube corresponding to the point D
(CERCLE 2).

Increment of load
DY of the point D
1: Mz =3.08670D+06Nm
DY (m)

Linear calculation:

Node
Reference
Aster
% diff
(COQUE_3D)
N1157 1.08875D03
1.08154D-03
0.6
N1104 1.08875D03
1.09424D-03 0.5
N1109 1.08875D03
1.08427D-03 0.4
N1099 1.08875D03
1.08427D-03 0.4

The tests of nonlinear calculations are tests of nonregression.

Elastoplastic calculation (not regression)

Node
Aster
N1157 1.079288D-03
N1104 1.09199D-03
N1109 1.082028D-03
N1099 1.082028D-03

Calculation great displacements (not regression):

Node
Aster
N1157 1.079777D-03
N1104 1.09299D-03
N1109 1.082769D-03
N1099 1.082769D
- 03

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/05/005/A

Code_Aster ®
Version
7.4
Titrate:
SSNV144 ­ Coude in inflection in great displacements

Date
:

07/11/05
Author (S):
J.M. PROIX, Key P. MASSIN
:
V6.04.144-A Page:
6/6

5
Summary of the results

This test makes it possible to validate the elements COQUE_3D into linear and nonlinear geometrical for one
real geometry having two curvatures. The results are close (less than 1%) to the reference
numerical in elasticity.

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/05/005/A

Outline document