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Code_Aster
®
Version
3
Titrate:
SSNV118 Test tensile shearing - Chaboche viscoplastic
Date:
21/07/99
Author (S):
P. GEYER
Key:
V6.04.118-A
Page:
1/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HI-75/96/044 - Ind A
Organization (S):
EDF/RNE/MTC
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
V6.04.118 document
SSNV118 - Tensile test shearing
with the viscoplastic model of Chaboche
Summary:
Nonlinear quasi static problem of mechanics of the structures in transient.
Analyze response of an element of volume to a loading of traction-shearing which imposes a state of
uniform stress-strain.
On an identical problem, one carries out two modelings to test the taking into account of the parameters
constant or depend on the temperature and integration with a tangent or elastic matrix.
This test validates the numerical integration of the model of behavior elastoviscoplastic of fascinating Chaboche
in account the phenomenon of memorizing of work hardening.
background image
Code_Aster
®
Version
3
Titrate:
SSNV118 Test tensile shearing - Chaboche viscoplastic
Date:
21/07/99
Author (S):
P. GEYER
Key:
V6.04.118-A
Page:
2/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HI-75/96/044 - Ind A
1
Problem of reference
1.1 Geometry
6
5
8
7
4
3
2
1
Z, dz
D
D
y, Dy
X, dx
Face YZ: (1, 4, 5, 8)
Face XZ: (1, 2, 5, 6)
Face 1YZ: (2, 3, 6, 7)
Face 1XZ: (4, 3, 8, 7)

D
: imposed pressure
D
: imposed shearing
D
D
D
1.2
Material properties
Isotropic elasticity E = 145.000 MPa
= 0.3
Model viscoplasticity VISCOCHAB
K
35 MPa
B
12
ETA
0.04
C2
65000 MPa
A_K
1.
M_R
2
C1
1950 MPa
M_2
4
A_R
0.65
G_R
210
­ 7
M_1
4
D2
0.552 10
­ 1
K_0
70 MPa S
1/NR
DRIVEN
19
D1
0.397 10
­ 3
G_X2
1. 10
­ 12
MPa
­ m1
S
­ 1
NR
24
Q_M
460
G_X1
2. 10
­ 13
MPa
­ m1
S
­ 1
G2_0
1300 MPa
ALP
0 MPa
Q_0
40 MPa
G1_0
50 MPa
A_I
0.5
QR_0
200 MPa
1.3
Boundary conditions and loadings
N6
dx = Dy = dz = 0
Face XZ: FX = ­
D
/4
N7
dx = Dy = 0
Face YZ: FY = ­
D
/4, FX = ­
D
/4
N2, N3
Dy = 0
Face 1XZ: FX =
D
/4
Face 1YZ: FY =
D
/4, FZ =
D/4
1.4 Conditions
initial
Null stresses and deformations with T = 0.
D
P
0
D
D
(T) and
D
(T) linear, the point P being reached into 10 S with
D
(10) = 150 MPa and
D
(10) = 60 MPa
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Code_Aster
®
Version
3
Titrate:
SSNV118 Test tensile shearing - Chaboche viscoplastic
Date:
21/07/99
Author (S):
P. GEYER
Key:
V6.04.118-A
Page:
3/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HI-75/96/044 - Ind A
2
Reference solution
2.1
Method of calculation used for the reference solution
One uses to establish the reference solution the software SIDOLO which allows simulation and
identification of laws of behavior.
The equations of the model are written by the user in FORTRAN in the form of a system of equations
first order differentials, solved by a method of Runge Kutta of command 4 with adaptive pitch.
2.2
Results of reference
xx
xy
xx
xy
xx
xx
xx
X
X
p R Q
,
,
,
,
,
,
1
2
at the moment P (T = 10 S) or
X1
and
X 2
are the variables
of kinematic work hardening,
p
cumulated plastic deformation,
()
R p Q
,
the variable of work hardening
isotropic and
the internal variable allowing the taking into account of the memory of work hardening.
2.3
Uncertainty on the solution
Uncertainty of SIDOLO.
2.4 References
bibliographical
[1]
SIDOLO, version 2.3, Note of use, École Nationale Supérieure of the Mines of Paris,
Center Materials, September 1995.
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Code_Aster
®
Version
3
Titrate:
SSNV118 Test tensile shearing - Chaboche viscoplastic
Date:
21/07/99
Author (S):
P. GEYER
Key:
V6.04.118-A
Page:
4/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HI-75/96/044 - Ind A
3 Modeling
With
3.1
Characteristics of modeling
Modeling 3D
6
5
8
7
4
3
2
1
Z
y
X
3.2
Characteristics of the mesh
1 HEXA8
3.3 Functionalities
tested
Order
Key word factor
Simple key word
Argument
Keys
DEFI_MATERIAU
VISCOCHAB
[U4.23.01]
STAT_NON_LINE
COMP_INCR
NEWTON
NEWTON
CONVERGENCE
RELATION
STAMP
ITER_LINE_MAXI
ITER_INTE_PAS
“VISCOCHAB”
“TANGENT”
5
10
[U4.32.01]
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Code_Aster
®
Version
3
Titrate:
SSNV118 Test tensile shearing - Chaboche viscoplastic
Date:
21/07/99
Author (S):
P. GEYER
Key:
V6.04.118-A
Page:
5/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HI-75/96/044 - Ind A
4
Results of modeling A
4.1 Values
tested
Identification
Reference
Aster
% difference
xx
150
149.991
­ 0.006
xy
60
59.949
­ 0.009
xx
1.49455 E2
1.50735 E2
0.856
xy
0.888452 E2
0.896134 E2
0.865
X
xx
1
12.4955
12.4880
­ 0.060
X
xx
2
30.0352
30.0546
0.065
p
1.69335 E2
1.70435 E2
0.709
R
8.36836
8.43440
0.789
Q
6.76633 E4
6.81646 E4
0.741
xx
1.33485 E2
1.34492 E2
0.754
4.2 Remarks
One uses only 11 increments of time in
Aster
, but the pitch of time is redécoupé by 10
for the local integration of the equations of the model.
SIDOLO uses several hundreds of pitch of times, calculated automatically.
4.3 Parameters
of execution
Version: 3.06
Machine: CRAY C90
System:
UNICOS
Overall dimension memory:
8 MW
Time CPU To use:
68.8 seconds
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Code_Aster
®
Version
3
Titrate:
SSNV118 Test tensile shearing - Chaboche viscoplastic
Date:
21/07/99
Author (S):
P. GEYER
Key:
V6.04.118-A
Page:
6/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HI-75/96/044 - Ind A
5 Modeling
B
5.1
Characteristics of modeling
Modeling 3D
6
5
8
7
4
3
2
1
Z
y
X
5.2
Characteristics of the mesh
1 HEXA8
5.3 Functionalities
tested
Order
Key word factor
Simple key word
Argument
Keys
DEFI_MATERIAU
VISCOCHAB_FO
[U4.23.01]
STAT_NON_LINE
COMP_INCR
NEWTON
NEWTON
CONVERGENCE
RELATION
STAMP
ITER_LINE_MAXI
ITER_INTE_PAS
“VISCOCHAB_FO”
“ELASTIC”
5
15
[U4.32.01]
background image
Code_Aster
®
Version
3
Titrate:
SSNV118 Test tensile shearing - Chaboche viscoplastic
Date:
21/07/99
Author (S):
P. GEYER
Key:
V6.04.118-A
Page:
7/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HI-75/96/044 - Ind A
6
Results of modeling B
6.1 Values
tested
Identification
Reference
Aster
% difference
xx
150
149.899
­ 0.067
xy
60
59.969
­ 0.052
xx
1.49455 E2
1.50922 E2
0.982
xy
0.888452 E2
0.897261 E2
0.991
X
xx
1
12.4955
12.4831
­ 0.100
X
xx
2
30.0352
30.0459
0.035
p
1.69335 E2
1.69886 E2
0.385
R
8.36836
8.40477
0.435
Q
6.76633 E4
6.79380 E4
0.406
xx
1.33485 E2
1.34060 E2
0.431
6.2 Remarks
The precision of the results is of the same command as for modeling A with a tangent matrix
rubber band and a smaller recutting of the pitch of time for the local integration of the equations of
model.
6.3 Parameters
of execution
Version: 3.06
Machine: CRAY C90
System:
UNICOS
Overall dimension memory:
8 MW
Time CPU To use:
94.5 seconds
background image
Code_Aster
®
Version
3
Titrate:
SSNV118 Test tensile shearing - Chaboche viscoplastic
Date:
21/07/99
Author (S):
P. GEYER
Key:
V6.04.118-A
Page:
8/8
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HI-75/96/044 - Ind A
7
Summary of the results
The equations of the model being strongly nonlinear, it is necessary to use increments of
small times to obtain a precise solution.
On this test presenting a geometry and boundary conditions simple, the recutting of the pitch of
time at the local level makes it possible to improve the precision of the results without increasing the time too much of
calculation.