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