Code_Aster
®
Version
5.0
Titrate:
SSNV154 - Triaxial compression test drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. AUBERT
Key
:
V6.04.154-A
Page:
1/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
Organization (S):
EDF/AMA, CNEPE
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
Document: V6.04.154
SSNV154 - Triaxial compression test 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 of an angle of -
/6 compared to axis X. Consequently, directions X, y, Z are not any more
main 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.
Code_Aster
®
Version
5.0
Titrate:
SSNV154 - Triaxial compression test drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. AUBERT
Key
:
V6.04.154-A
Page:
2/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
1
Problem of reference
1.1 Geometry
Z
X
y
E
L
H
C
With
B
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 10
3
kPa
= 0,15037594
Parameters CJS3:
= - 0,55
= 0,82 R
m
= 0,05
R
C
= 0,265
N = 0,6
K
COp
= 25,5 10
3
kPa
B = 7.0 kPa
µ = 0.021
p
Co
= - 600 kPa
C = 30.0
P
has
= - 100 kPa
1.3
Initial conditions, boundary conditions, and loading
Phase 1:
One brings the sample in a homogeneous state:
xx
yy
zz
0
0
0
=
=
, by imposing the pressure of
containment corresponding on the front, side straight line and higher faces. Displacements are
locked on the faces postpones (
U
X
= 0
), side left (
U
y
= 0
) and lower (
U
Z
= 0
).
Phase 2:
One maintains displacements locked on the faces postpones (
U
X
= 0
), side left (
U
y
= 0
) and
lower (
U
Z
= 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).
height:
H = 1 m
width:
L
= 1 m
thickness:
E = 1 m
Code_Aster
®
Version
5.0
Titrate:
SSNV154 - Triaxial compression test drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. AUBERT
Key
:
V6.04.154-A
Page:
3/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
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
Stresses
xx
,
yy
and
zz
at point A.
2.3 Bibliography
[1]
Board, “FLAC (Fast Lagrangian Analysis off Continued) Version 2.20. U.S. NRC”,
NUREG/CR-5430, October 1989.
[2]
“Flac Fast Lagrangian Analysis off Continued. Theory and Background. ” Itasca Consulting
Group.
Code_Aster
®
Version
5.0
Titrate:
SSNV154 - Triaxial compression test drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. AUBERT
Key
:
V6.04.154-A
Page:
4/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
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:
xx
yy
0
0
=
= 400 kPa.
Level 3 of model CJS
3.2
Characteristic of the mesh
A number of nodes: 4
A number of meshs and types: 1
QUAD4
and 4
SEG2
3.3 Functionalities
tested
Controls
DEFI_MATERIAU CJS
STAT_NON_LINE COMP_INCR
RELATION
“CJS”
Code_Aster
®
Version
5.0
Titrate:
SSNV154 - Triaxial compression test drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. AUBERT
Key
:
V6.04.154-A
Page:
5/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
4
Results of modeling A
4.1 Values
tested
For
xx
yy
0
0
=
= 400 kPa
Localization Number
of command
deformation
axial
zz
(%)
stress
(kPa)
Reference
FLAC 2D
Aster %
difference
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
Overall dimension memory: 100 MO
Time CPU To use: 63 S
Code_Aster
®
Version
5.0
Titrate:
SSNV154 - Triaxial compression test drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. AUBERT
Key
:
V6.04.154-A
Page:
6/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
5 Modeling
B
5.1 Geometry
Z
y
X
E
L
H
With
/6
B
C
D
E
F
G
H
Co-ordinates of the points (in meters):
With
B
C
D
X 0. 0.
1. 1.
y 0. 0.8660254037844
5
0.8660254037844
5
0.
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 mesh
A number of nodes: 8
A number of meshs and types: 1
HEXA8
and 6
QUA4
5.4 Functionalities
tested
Controls
DEFI_MATERIAU CJS
STAT_NON_LINE COMP_INCR
RELATION
“CJS”
height:
H = 1 m
width:
L
= 1 m
thickness:
E = 1 m
Code_Aster
®
Version
5.0
Titrate:
SSNV154 - Triaxial compression test drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. AUBERT
Key
:
V6.04.154-A
Page:
7/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
6
Results of modeling B
6.1 Values
tested
For containment: 400 kPa
Localization Number
of command
deformation
axial
zz
(%)
stress
(kPa)
Reference
Aster %
difference
Not A
10
2.0%
xx
400.0 400.000
<
10
6
50
10.0
%
xx
400.0 400.000
< 10
6
100
20.0
%
xx
400.0 400.000
< 10
6
10 2.0
%
yy
53.221
53.22098 <
10
6
50
10.0
%
yy
63.7665 63.76653
< 10
6
100
20.0
%
yy
63.7165 63.71645
< 10
6
10 2.0
%
zz
79.6629 79.66294
< 10
6
50
10..0
%
zz
111.3 111.29959 < 10
6
100
20.0
%
zz
111.149 111.14935
< 10
6
10
2.0
%
yz
22.8994 22.89941
< 10
6
50
10.0
%
yz
41.1648 41.16483
< 10
6
100
20.0
%
yz
41.0781 41.07809
< 10
6
6.2 Parameters
of execution
Version:
5.07.01
Machine:
SGI-ORIGIN 2000
System:
IRIX64
Overall dimension memory: 32MO
Time CPU To use: 106 S
Code_Aster
®
Version
5.0
Titrate:
SSNV154 - Triaxial compression test drained with model CJS (level 3)
Date:
04/03/02
Author (S):
C. CHAVANT, pH. AUBERT
Key
:
V6.04.154-A
Page:
8/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
7
Summary of the results
The results of Aster coincide with those of FLAC with a lower deviation than 0,05%.