Code_Aster
®
Version
8.1
Titrate:
SSNA112 - Test of wrenching for the study of the steel-concrete connection
Date:
29/06/05
Author (S):
S. MICHEL-PONNELLE, NR. DOMINGUEZ
Key
:
V6.01.112-B
Page:
1/8
Manual of Validation
V6.01 booklet: Non-linear statics into axisymmetric
HT-66/05/005/A
Organization (S):
EDF-R & D/AMA
Manual of Validation
V6.01 booklet: Nonlinear statics into axisymmetric
Document: V6.01.112
SSNA112 axisymmetric Test of wrenching
(Borderie & Pijaudier- Pooch) for the study of
steel-concrete connection: law JOINT_BA
Summary:
In this case test of mechanics one modelized the test of wrenching carried out by Borderie & Pijaudier-
Pooch [bib1] of which the goal was to study the influence of the state of stress in the matrix on the properties
mechanics of the interface. The geometrical data and the characteristics materials result from their
report/ratio, and the numerical results will be compared with the experimental results.
For axisymmetric modeling, one uses elements QUAD4 for the concrete and steel, in combination
with elements gasket for the interface (see Doc. [R3.06.09]). The concrete and steel are considered elastic so
to test only nonthe linearity of the law of behavior of the connection steel concrete, JOINT_BA (see
document [R7.01.21]). One carries out a monotonous calculation with the displacements imposed at the end of the bar
of steel.
Code_Aster
®
Version
8.1
Titrate:
SSNA112 - Test of wrenching for the study of the steel-concrete connection
Date:
29/06/05
Author (S):
S. MICHEL-PONNELLE, NR. DOMINGUEZ
Key
:
V6.01.112-B
Page:
2/8
Manual of Validation
V6.01 booklet: Non-linear statics into axisymmetric
HT-66/05/005/A
1
Problem of reference
1.1
Geometry and boundary conditions
Appear 1.1-a: Geometry and boundary conditions
1.2
Properties of material
Steel: rubber band
E = 2.1x10
+5
MPa,
= 0.3
Concrete: rubber band
E = 1.55x10
+4
MPa,
= 0.17
Element of gasket:
·
law of behavior ELAS with the following parameters:
E = 1.55x10
+4
MPa,
= 0.17
·
law of behavior JOINT_BA with the following parameters:
- Initial Parameters:
coefficient of penetration:
Hpen
= 0.64 mm
(key word: HPEN)
modulate rigidity:
bound
G
= 6.65x10
+3
MPa
(key word: GTT)
80
10
80
45
U = 6 mm
Code_Aster
®
Version
8.1
Titrate:
SSNA112 - Test of wrenching for the study of the steel-concrete connection
Date:
29/06/05
Author (S):
S. MICHEL-PONNELLE, NR. DOMINGUEZ
Key
:
V6.01.112-B
Page:
3/8
Manual of Validation
V6.01 booklet: Non-linear statics into axisymmetric
HT-66/05/005/A
- Parameters of tangential damage:
threshold of elastic strain:
0
= 5x10
- 4
(key word: GAMD0)
coefficient of damage area 1:
1
AD
= 1.0
(key word: AD1)
coefficient of damage area 1:
1
Data base
= 0.5
(key word: BD1)
threshold of the great slips:
2
= 9.6x10
- 1
(key word: GAMD2)
coefficient of damage area 2:
2
AD
= 4x10
- 5
MPa
- 1
(key word: AD2)
coefficient of damage area 2:
2
Data base
= 1.0
(key word: BD2)
- Parameters for the friction of the fissures and containment:
coefficient material by friction:
= 10.0 MPa
(key word: VIFROT)
coefficient by kinematic work hardening:
= 4x10
- 1
MPa
- 1
(key word: F)
coefficient of containment:
C
= 1.0
(key word: FC)
- Parameters of normal damage:
normal deformation criticizes (opening):
0
NR
= 9x10
- 1
(key word: EPSTR0)
coefficient of normal damage:
NR
AD
= 1x10
- 9
MPa
- 1
(key word: ADN)
coefficient of normal damage:
NR
Data base
= 1.5
(key word: BDN)
1.3
Boundary conditions and loadings
Null displacements imposed (embedding) on the side face of the elements of the concrete.
The axis of rotation is fixed in the middle of the steel bar.
The mechanical loading into monotonous is applied in the form of displacements imposed to
the end of the steel bar in two stages:
·
20 increments of 0.005 mm, for
U
= {0 to 0.1 mm}
·
118 increments of 0.05 mm, for
U
= {0.1 to 6 mm}
Code_Aster
®
Version
8.1
Titrate:
SSNA112 - Test of wrenching for the study of the steel-concrete connection
Date:
29/06/05
Author (S):
S. MICHEL-PONNELLE, NR. DOMINGUEZ
Key
:
V6.01.112-B
Page:
4/8
Manual of Validation
V6.01 booklet: Non-linear statics into axisymmetric
HT-66/05/005/A
2
Reference solution
It is about a numerical comparison - experimental. The work of Borderie & Pijaudier-Pooch
[bib1] consisted in a trial run of wrenchings carried out on fibers and
reinforcements for reinforced concrete. The object of these tests was to study the influence of the state of stress in
the matrix on the mechanical properties of the interface.
Each specimen was a cube of 80x80x80 mm whose concrete paste was Grade C30/37 (gravel
of 16 mm) with a resistance to the moment of the test (three days after the casting and with a processing
4 hours thermics) of 14.5 MPa, a Young modulus of 15.500 MPa and a Poisson's ratio
from 0,17. For the reinforcements, they used deformed bars 8 mms in diameter, with
a length of steel-concrete contact of 45 mm, plus 10 mm free at the edge of the concrete, which allowed
to eliminate the singularities in the field from the concrete stresses in the embedded surface of the cube.
The test was carried out with controlled displacements (
u&
= 8.3 X 10th-3 m/s) and four levels of
containment: 0, 5, 10 and 15 MPa, constant during each experiment.
3 Bibliography
[1]
BORDERIE C. & PIJAUDIER-CABOT G. - experimental Study of the behavior of
reinforced materials: Experimental determination of the laws of behavior of the interface
matrix fiber. Laboratory of Mechanics and Technology (LMT)
; ENS
Cachan/CNRS/University Paris 6; Contract I 70/1F 3146 with Electricity of France, 1994
Code_Aster
®
Version
8.1
Titrate:
SSNA112 - Test of wrenching for the study of the steel-concrete connection
Date:
29/06/05
Author (S):
S. MICHEL-PONNELLE, NR. DOMINGUEZ
Key
:
V6.01.112-B
Page:
5/8
Manual of Validation
V6.01 booklet: Non-linear statics into axisymmetric
HT-66/05/005/A
4 Modeling
With
4.1
Characteristics of modeling
It is about an axisymmetric modeling 2D, where one can identify 2 groups of elements:
Axisymmetric modeling (key word
AXIS
) for the elements of the concrete and steel.
Modeling fissures axisymmetric (key word AXIS_JOINT) for the element of gasket.
The concrete and steel are modelized with elements QUAD4.
The interface is modelized with degenerated elements QUAD4 (confused nodes).
Appear 4.1-a: Modeling of the test into axisymmetric
4.2
Characteristics of the mesh
A number of nodes: 94 (with 20 confused nodes)
A number of meshs and type: 11 QUAD4 for steel
+ 9 QUAD4 for the interface
+ 54 QUAD4 for the concrete.
Embedding
Center
of
rotation
Interface
Code_Aster
®
Version
8.1
Titrate:
SSNA112 - Test of wrenching for the study of the steel-concrete connection
Date:
29/06/05
Author (S):
S. MICHEL-PONNELLE, NR. DOMINGUEZ
Key
:
V6.01.112-B
Page:
6/8
Manual of Validation
V6.01 booklet: Non-linear statics into axisymmetric
HT-66/05/005/A
4.3 Functionalities
tested
The law of behavior JOINT_BA local version in 2D.
Controls
Options
DEFI_MATERIAU JOINT_BA
HPEN
GTT
GAMD0
AD1
BD1
GAMD2
AD2
BD2
VIFROT
F
FC
EPSTR0
ADN
BDN
STAT_NON_LINE COMP_INCR
RELATION
JOINT_BA
5
Results of modeling A
5.1 Values
tested
One tests the components xy element which correspond to the tangential components of the law
local of behavior in the interface, starting from the stress field SIEF_ELGA. Values
are tested at the point of Gauss 2 of the element gasket, with 4 pitches of different times: at the beginning of
loading, during the phase of growth of the damage, in the peak of resistance
maximum and after the peak of the resistance of the connection.
Component field SIEF_ELGA SITX
Identification Reference
Code_Aster %
difference
For an imposed displacement
TT
U
= 0.2 mm
- 7.20 E+00
- 7.39825 E+00
2.753
For an imposed displacement
TT
U
= 0.8 mm
- 1.14 E+01
- 1.17820 E+01
- 3.351
For an imposed displacement
TT
U
= 1.0 mm
- 1.26 E+01
- 1.21161 E+01
- 3.841
For an imposed displacement
TT
U
= 1.6 mm
- 1.22 E+01
- 1.19952 E+01
- 1.679
Code_Aster
®
Version
8.1
Titrate:
SSNA112 - Test of wrenching for the study of the steel-concrete connection
Date:
29/06/05
Author (S):
S. MICHEL-PONNELLE, NR. DOMINGUEZ
Key
:
V6.01.112-B
Page:
7/8
Manual of Validation
V6.01 booklet: Non-linear statics into axisymmetric
HT-66/05/005/A
5.2
Evolution of the damage
To observe the coherence of the evolution of the damage in the various elements of
connection, one builds the graphics of the variable of damage compared to displacement
imposed.
Code_Aster
®
Version
8.1
Titrate:
SSNA112 - Test of wrenching for the study of the steel-concrete connection
Date:
29/06/05
Author (S):
S. MICHEL-PONNELLE, NR. DOMINGUEZ
Key
:
V6.01.112-B
Page:
8/8
Manual of Validation
V6.01 booklet: Non-linear statics into axisymmetric
HT-66/05/005/A
6
Summary of the results
With lower deviations than 5.0% compared to the experimental results obtained by Borderie &
Pijaudier-pooch [bib1], one considers that the axisymmetric simulation of the test of wrenching is
satisfactory. However, in order to test the stability of the law of behavior in combination with
other laws (law MAZARS for the concrete, for example), it will be necessary to decrease the size of the pitches of time
by considering that the other laws are made normally for formulations into small
deformations.