Code_Aster ®
Version
5.0
Titrate:
SSNA102 - Contact multicorps elastic


Date:
15/10/01
Author (S):
NR. TARDIEU Key
:
V6.01.102-A Page:
1/8

Organization (S): EDF/MTI/MN

Handbook of Validation
V6.01 booklet:Nonlinear statics into axisymmetric
Document: V6.01.102

SSNA102 - Contact multicorps elastic

Summary:

This problem of nonlinear statics of an axisymmetric structure makes it possible to test the two alternatives of
the algorithm of contact in great displacements.
Calculation consists of the modeling of a structure made up of several elastic bodies in contact
unilateral without friction. This calculation already was object IPSI-Phi2AS the case-test describes in the note
HI-75/97/034/0. The reference solution comes from calculations carried out with codes ABAQUS, SYSTUS and
The SAMCEF software.
Handbook of Validation
V6.01 booklet: Nonlinear statics into axisymmetric
HI-75/01/010/A

Code_Aster ®
Version
5.0
Titrate:
SSNA102 - Contact multicorps elastic


Date:
15/10/01
Author (S):
NR. TARDIEU Key
:
V6.01.102-A Page:
2/8

1
Problem of reference

1.1 Geometry

Model: Axisymmetric
Units: mm

LCD1

10.

2.

PA1

PP2
Z

5.

PM2
R

PP3

10.

4.
LBC4

PA4

20.

1.2
Properties of material

Linear elastic material of characteristics: E = 200000. MPa

= 0.3

1.3
Boundary conditions and loadings

·
DR. and DZ blocked on LBC4
·
DZ imposed - 2.0 mm on LCD1
·
Connections between degrees of freedom:
DZ (PA1) = DZ (PP2)
DZ (PM2) = DZ (PP3)
·
Conditions of unilateral contact between each face of the solids in opposite, is 3
couples of paired surfaces
Handbook of Validation
V6.01 booklet: Nonlinear statics into axisymmetric
HI-75/01/010/A

Code_Aster ®
Version
5.0
Titrate:
SSNA102 - Contact multicorps elastic


Date:
15/10/01
Author (S):
NR. TARDIEU Key
:
V6.01.102-A Page:
3/8

2
Reference solution

2.1
Method of calculation used for the reference solution

Average of the results obtained by various computer codes in mechanics, ABAQUS, SYSTUS,
The SAMCEF software, within the framework of a case test IPSI-2AS [bib1].

2.2
Results of reference

Vertical displacement of point PA4:
ABAQUS: - 0.83 mm


SYSTUS: - 0.82 mm is - 0 8
. 1mm
The SAMCEF software: - 0.78 mm



Vertical component of the reaction to embedding LBC4:
ABAQUS: 110270 NR


SYSTUS: 109500 NR is 108257 NR
The SAMCEF software: 105000 NR



NB:

The efforts calculated by Aster into axisymmetric are it by radian. The value to be aimed is thus
108257/2 = 17229 58
. NR/rd

2.3
Uncertainties on the solution

Dispersion around the average value of vertical displacement in PA4 is 4%. Dispersion
around the vertical reaction to embedding is 3%.

2.4 References
bibliographical

[1]
I. VAUTIER: “Example of use of the functionalities of contact in great displacements
in Code_Aster “, notes HI-75/97/034/0.
Handbook of Validation
V6.01 booklet: Nonlinear statics into axisymmetric
HI-75/01/010/A

Code_Aster ®
Version
5.0
Titrate:
SSNA102 - Contact multicorps elastic


Date:
15/10/01
Author (S):
NR. TARDIEU Key
:
V6.01.102-A Page:
4/8

3 Modeling
With

3.1
Characteristics of modeling

One uses the algorithm algoco.f i.e here the algorithm by defect of key word CONTACT. It is one
algorithm of active constraints where one activates/decontaminates the connections until reaching one by one one
state of contact satisfying the conditions kinematics, before turning over towards an iteration of
Newton.

3.2
Characteristics of the grid

Nodes: 4620 nodes

Meshs: 1348 QUAD8, 114 TRI6, 2213 SEG3

GIBI FECIT


3.3 Functionalities
tested

Commands Key word
factor
Key word
AFFE_CHAR_MECA CONTACT
METHODE
CONTRAINTE
STAT_NON_LINE


Handbook of Validation
V6.01 booklet: Nonlinear statics into axisymmetric
HI-75/01/010/A

Code_Aster ®
Version
5.0
Titrate:
SSNA102 - Contact multicorps elastic


Date:
15/10/01
Author (S):
NR. TARDIEU Key
:
V6.01.102-A Page:
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4
Results of modeling A

4.1 Values
tested

Identification Moments Reference
Aster %
difference
DY not PA4
1.
­ 0.81
­ 0.83844
3.5
FY Bord LBC4
1.
17229.58
17443.16
1.2

4.2 Remarks

Calculation converges in a step of loading.

4.3 Parameters
of execution

Version: 5.04

Machine: SGI-Origin2000-R12000

Obstruction memory: 50 Mo
Time CPU To use: 91.11 seconds
Handbook of Validation
V6.01 booklet: Nonlinear statics into axisymmetric
HI-75/01/010/A

Code_Aster ®
Version
5.0
Titrate:
SSNA102 - Contact multicorps elastic


Date:
15/10/01
Author (S):
NR. TARDIEU Key
:
V6.01.102-A Page:
6/8

5 Modeling
B

5.1
Characteristics of modeling

One uses the algorithm algocp.f i.e here the algorithm given by METHODE: “LAGRANGIEN” of the key word
CONTACT. One activates/decontaminates the connections per package without seeking to reach a state of contact
satisfying the conditions kinematics before turning over towards an iteration of Newton.

5.2
Characteristics of the grid

Nodes: 4620 nodes

Meshs: 1348 QUAD8, 114 TRI6, 2213 SEG3

GIBI FECIT


5.3 Functionalities
tested

Commands Key word
factor
Key word
AFFE_CHAR_MECA CONTACT
METHODE
LAGRANGIEN
STAT_NON_LINE


Handbook of Validation
V6.01 booklet: Nonlinear statics into axisymmetric
HI-75/01/010/A

Code_Aster ®
Version
5.0
Titrate:
SSNA102 - Contact multicorps elastic


Date:
15/10/01
Author (S):
NR. TARDIEU Key
:
V6.01.102-A Page:
7/8

6
Results of modeling B

6.1 Values
tested

Identification Moments Reference
Aster %
difference
DY not PA4
1.
­ 0.81
­ 0.84110
3.84
FY Bord LBC4
1.
17229.58
17491.52
1.52

6.2 Remarks

Calculation converges in two steps of loading (difference with modeling A due to nature of
the algorithm).

6.3 Parameters
of execution

Version: 5.04

Machine: SGI-Origin2000-R12000

Obstruction memory: 50 Mo
Time CPU To use: 210.29 seconds
Handbook of Validation
V6.01 booklet: Nonlinear statics into axisymmetric
HI-75/01/010/A

Code_Aster ®
Version
5.0
Titrate:
SSNA102 - Contact multicorps elastic


Date:
15/10/01
Author (S):
NR. TARDIEU Key
:
V6.01.102-A Page:
8/8

7
Summary of the results

The results are satisfactory taking into account the diversity of the origin of the reference solution.
Although the two algorithms of contact give identical results in displacement and in
force, returned effective surfaces of contact differ slightly. Sights respective natures
of the two algorithms, that is completely comprehensible. To obtain the same ones exactly
results, it is necessary to make calculations in 10 steps of time.
Lastly, the difference in time CPU between the two algorithms is explained by the more significant number
iterations of Newton carried out by the algorithm algocp.f (METHODE: “LAGRANGIEN”).
Handbook of Validation
V6.01 booklet: Nonlinear statics into axisymmetric
HI-75/01/010/A

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