Code_Aster
®
Version
6.0
Titrate:
SSNV153 - Contact pulley-cord
Date:
19/08/02
Author (S)
:
P. MASSIN, Mr. ZARROUG
Key:
V6.04.153-A
Page:
1/6
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
Organization (S)
: EDF/AMA, ECP
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
Document: V6.04.153
SSNV153 - Contact pulley - cord
Summary:
This problem corresponds to a quasi-static analysis of a problem of mechanics with contact without
friction. It is about a cord posed on a pulley, whose interior surface is embedded, and fired from two
sides with an imposed vertical displacement.
This test, treated in 2D with elements QUAD4 is implemented to validate the smoothing of the normal of
surfaces of contact.
This test is based on results 2D suggested by Papadopolous [bib1].
Code_Aster
®
Version
6.0
Titrate:
SSNV153 - Contact pulley-cord
Date:
19/08/02
Author (S)
:
P. MASSIN, Mr. ZARROUG
Key:
V6.04.153-A
Page:
2/6
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
1
Problem of reference
1.1 Geometry
Thickness of the cord ep = 1 Misters.
Thickness of the pulley has = 1 Misters.
Position of the points of reference on the surface of contact (mm)
X y
To 0 4 0
B 0 3 0
C 0 3 0
1.2
Material properties
Plate for the pulley and the cord:
Poisson's ratio: 0.4762
Young modulus: 147.619 10
5
NR/m
2
Finite elements of contact:
Integration: Nodes
Parameter of the method:
Coef_regu_cont
=1.
Surface contact
Interior surface
embedded
Vertical displacements
imposed
With
X
y
B
C
D
Code_Aster
®
Version
6.0
Titrate:
SSNV153 - Contact pulley-cord
Date:
19/08/02
Author (S)
:
P. MASSIN, Mr. ZARROUG
Key:
V6.04.153-A
Page:
3/6
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
1.3
Boundary conditions and loadings
The pulley is locked:
·
on its surface displacement interns is null in two directions X and Y.
No boundary conditions is imposed on the cord except that of the contact.
Loading:
·
two vertical displacements are imposed on the two ends of the cord u=1
2
Reference solution
2.1
Method of calculation used for the reference solution
The reference solution comes from results obtained in [bib1].
2.2
Results of reference
Tangential displacements (according to X) at points A B C of the surface of contact.
Value of
yy
at the point C (and thus that of the LAGS_C)
2.3 Reference
bibliographical
[1]
P. PAPADOPOULOS “Numerical formulations for contact problems with friction” Newspaper off
Theorical and Applied Mechanics GAUTHIER-VILLARS
Code_Aster
®
Version
6.0
Titrate:
SSNV153 - Contact pulley-cord
Date:
19/08/02
Author (S)
:
P. MASSIN, Mr. ZARROUG
Key:
V6.04.153-A
Page:
4/6
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
3 Modeling
With
3.1
Characteristics of modeling
Modeling:
2d_PLAN
for the solid elements (QUAD4)
The pulley is with a grid with a regular mesh using only elements QUAD4. There is the same one
a number of nodes on interior and external surface. For the cord the mesh is also
regular and includes/understands only elements QUAD4. There are 8 meshs in the thickness of the cord.
3.2
Characteristics of the mesh
A number of nodes:
807
A number of meshs and types:
703 QUAD4 and 311 SEG2
3.3 Functionalities
tested
Controls
CONTACT
METHOD
“CONTINUES”
CONTACT
INTEGRATION
“NODE”
CONTACT
SMOOTHING
“YES”
CONTACT
COEF_REGU_CONT
CONTACT
COEF_REGU_FROT
STAT_NON_LINE
4
Results of modeling A
4.1 Values
tested
Identification Reference
Aster %
difference
DX at point A
0.0
- 1.8289243E-08
1.83E-08
DX at the point B
0.0
- 1.6557395E-08
- 1.66E-08
DX at the point C
0.0
1.8398391E-09
1.84E-09
SIYY at the point C
- 5.97E+05 - 6.0271214E+05
0.957%
4.2 Parameters
of execution
Version: 5.04.14
Machine: CLASTER
System: IRIX64
Overall dimension memory:
16 megawords
Time CPU To use: 129.59 seconds
Code_Aster
®
Version
6.0
Titrate:
SSNV153 - Contact pulley-cord
Date:
19/08/02
Author (S)
:
P. MASSIN, Mr. ZARROUG
Key:
V6.04.153-A
Page:
5/6
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
5
Summary of the results
In this case test, two surfaces of contact are not plane. The normal thus changes one
net with another. This discontinuity generates problems of pairing which have large
influence on calculation. Among these problems, one finds the problem of dissymetrisation, i.e to find
results which do not respect the symmetry of the problem. For this case test, the problem is
perfectly symmetrical (geometries, boundary conditions and loading) according to axis Y. Without
regularization of the normal a dissymmetry appears on axis X. Indeed, displacements
horizontal of the points A, B and C which are on the axis have there then nonnull values which
do not respect the total symmetry of the problem.
With the regularization of the normal, the solution obtained by using the method continues, respects
perfectly symmetry. It should however be noted that the maillor gibi, used in this case test, does not give
not a perfectly symmetrical mesh and that problems of flares deteriorate very slightly
the quality of the solution.
This problem is dealt with with the method
CONTINUOUS
, of the key word
CONTACT
. Integration is made with
level of the nodes of the mesh. A detailed attention on the choice of the potential areas of
contact is to be taken into account in these problems of nonplane surfaces.
Code_Aster
®
Version
6.0
Titrate:
SSNV153 - Contact pulley-cord
Date:
19/08/02
Author (S)
:
P. MASSIN, Mr. ZARROUG
Key:
V6.04.153-A
Page:
6/6
Manual of Validation
V6.04 booklet: Nonlinear statics of the voluminal structures
HT-66/02/001/A
Intentionally white left page.