Code_Aster ®
Version
5.0
Titrate:
SSNV154 - Triaxial Essai drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. Key AUBERT
:
V6.04.154-A Page:
1/8

Organization (S): EDF/AMA, CNEPE
Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
Document: V6.04.154
SSNV154 - Triaxial Essai drained with model CJS
(level 3)

Summary

This test makes it possible to validate level 3 of model CJS. It is about a triaxial compression test in drained condition.
calculations are carried out only on the solid part of the ground without hydraulic coupling. The level of
containment is 400 KPa.
By reason of symmetry, one is interested only in the eighth of a sample subjected to a triaxial compression test. Two
modelings are presented. Modeling A is axisymmetric. In modeling B, 3D, the sample
tested is turned from an angle of -/6 compared to axis X. Consequently, directions X, y, Z are not any more
principal directions. That makes it possible to validate the operations of numerical integration of the model which act on
nondiagonal terms of the tensors of the strains and the stresses.
It is about a test of nonregression. Nevertheless, results obtained with Code_Aster for model CJS3
are compared with those obtained with a private version of software FLAC - 2D.
Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A

Code_Aster ®
Version
5.0
Titrate:
SSNV154 - Triaxial Essai drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. Key AUBERT
:
V6.04.154-A Page:
2/8

1
Problem of reference

1.1 Geometry

Z
E
height:
H = 1 m
width:
L
= 1 m
thickness:
E = 1 m
C
H
With
B
y
X
L


Co-ordinates of the points (in meters):

With
B
C
X 0. 0.
0.5
y 0. 1.
0.5
Z 0. 0.
0.5

1.2
Material property

E = 35,6616541 103 kPa
= 0,15037594

Parameters CJS3:
= - 0,55
= 0,82 Rm = 0,05
Rc = 0,265
N = 0,6

K p
O = 25,5 103 kPa
B = 7.0 kPa
µ = 0.021
pco = - 600 kPa

C = 30.0

Pa = - 100 kPa


1.3
Initial conditions, boundary conditions, and loading

Phase 1:
One brings the sample in a homogeneous state: 0 = 0 = 0
xx
yy
zz, by imposing the pressure of
containment corresponding on the front, side straight line and higher faces. Displacements are
blocked on the faces postpones (ux = 0), side left (uy = 0) and lower (uz = 0).

Phase 2:
One maintains displacements blocked on the faces postpones (ux = 0), side left (uy = 0) and
lower (uz = 0), as well as the confining pressure on the front faces and side straight line. One
apply a displacement imposed to the higher face: U (T)
Z
, in order to obtain a deformation
zz = - 20% (counted starting from the beginning of phase 2).
Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A

Code_Aster ®
Version
5.0
Titrate:
SSNV154 - Triaxial Essai drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. Key AUBERT
:
V6.04.154-A Page:
3/8

2
Reference solution

2.1
Method of calculation used for the reference solution

The results obtained with a private version of software FLAC 2D are used as reference.

2.2
Results of reference

Constraints xx, yy and zz at point A.

2.3 Bibliography

[1]
Board, “FLAC (Fast Lagrangian Analysis off Continua) Version 2.20. U.S. NRC”,
NUREG/CR-5430, October 1989.
[2]
“Flac Fast Lagrangian Analysis off Continua. Theory and Background. ” Itasca Consulting
Group.

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A

Code_Aster ®
Version
5.0
Titrate:
SSNV154 - Triaxial Essai drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. Key AUBERT
:
V6.04.154-A Page:
4/8

3 Modeling
With

3.1
Characteristic of modeling

3D:
y
Z
X

Cutting: 1 in height, 1 in width.

Loading of phase 1:
Confining pressure: 0 = 0
xx
yy = ­ 400 kPa.
Level 3 of model CJS

3.2
Characteristic of the grid

A number of nodes: 4
A number of meshs and types: 1 QUAD4 and 4 SEG2

3.3 Functionalities
tested

Commands




DEFI_MATERIAU CJS



STAT_NON_LINE COMP_INCR
RELATION
“CJS”


Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A

Code_Aster ®
Version
5.0
Titrate:
SSNV154 - Triaxial Essai drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. Key AUBERT
:
V6.04.154-A Page:
5/8

4
Results of modeling A

4.1 Values
tested

For 0 = 0
xx
yy = ­ 400 kPa

Localization Numéro deformation
constraint
Reference
Aster %
difference
of command
axial
(kPa)
zz (%)
FLAC 2D
Not A 10
­ 4.0%

xx
­ 400.0
­ 400.000 <
0.05
50
­ 20.0
%
xx
­ 400.0 ­ 400.000 < 0.05

10
­ 4.0%
zz
­ 400.0
­ 400.000 < 0.05
50
­ 20.0
%
zz
­ 400.0 ­ 400.000 < 0.05

2
­ 0.8%
yy
­ 667.209
­ 667.2087 <
0.05
5
­ 2.0
%
yy
­ 917.634
­ 917.6343 <
0.05
10
­ 4.0
%
yy
­ 1184.57
­ 1184.5705 <
0.05
20
­ 8.0
%
yy
­ 1337.38
­ 1337.3821 <
0.05
34
­ 12.0
%
yy
­ 1351.76
­ 1351.7551 <
0.05
40
­ 16.0
%
yy
­ 1350.80
­ 1350.8029 <
0.05
50
­ 20.0
%
yy
­ 1348.54
­ 1348.5422 <
0.05

4.2 Parameters
of execution

Version:
5.07.01


Machine:
SGI-ORIGIN 2000
System:
IRIX64
Obstruction memory: 100 MO
Time CPU To use: 63 S
Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A

Code_Aster ®
Version
5.0
Titrate:
SSNV154 - Triaxial Essai drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. Key AUBERT
:
V6.04.154-A Page:
6/8

5 Modeling
B

5.1 Geometry
Z
/6th
F
H
height:
H = 1 m
width:
L
= 1 m
thickness:
E = 1 m
H
G
With
y
B
X
D
E
L
C


Co-ordinates of the points (in meters):

With
B
C
D
X 0. 0.
1. 1.
y 0. 0.8660254037844
0.8660254037844
0.
5
5
Z 0. ­ 0.5
­ 0.5
0.

5.2
Characteristic of modeling

3D:

Cutting:1 in height, in width and thickness.

Loading of phase 1:
Confining pressure: ­ 400 kPa.
Level 3 of model CJS

5.3
Characteristic of the grid

A number of nodes: 8
A number of meshs and types: 1 HEXA8 and 6 QUA4

5.4 Functionalities
tested

Commands




DEFI_MATERIAU CJS



STAT_NON_LINE COMP_INCR
RELATION
“CJS”

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A

Code_Aster ®
Version
5.0
Titrate:
SSNV154 - Triaxial Essai drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. Key AUBERT
:
V6.04.154-A Page:
7/8

6
Results of modeling B

6.1 Values
tested

For containment: ­ 400 kPa

Localization Numéro deformation
constraint
Reference
Aster %
of command
axial zz (%)
(kPa)
difference
Not A
10
­ 2.0%
xx
­ 400.0 ­ 400.000
<
10­6
50
­ 10.0
%
xx
­ 400.0 ­ 400.000
< 10­6
100
­ 20.0
%
xx
­ 400.0 ­ 400.000
< 10­6

10 ­ 2.0
% yy
­ 53.221
­ 53.22098 <
10­6
50
­ 10.0
%
yy
­ 63.7665 ­ 63.76653
< 10­6
100
­ 20.0
%
yy
­ 63.7165 ­ 63.71645
< 10­6

10 ­ 2.0
% zz
­ 79.6629 ­ 79.66294
< 10­6
50
­ 10..0
%
zz
­ 111.3 ­ 111.29959 < 10­6
100
­ 20.0
%
zz
­ 111.149 ­ 111.14935
< 10­6
10
­ 2.0
%
yz
­ 22.8994 ­ 22.89941
< 10­6
50
­ 10.0
%
yz
­ 41.1648 ­ 41.16483
< 10­6
100
­ 20.0
%
yz
­ 41.0781 ­ 41.07809
< 10­6

6.2 Parameters
of execution

Version:
5.07.01


Machine:
SGI-ORIGIN 2000
System:
IRIX64
Obstruction memory: 32MO
Time CPU To use: 106 S

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A

Code_Aster ®
Version
5.0
Titrate:
SSNV154 - Triaxial Essai drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. Key AUBERT
:
V6.04.154-A Page:
8/8

7
Summary of the results

The results of Aster coincide with those of FLAC with a lower deviation than 0,05%.

Handbook of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A

Outline document