Code_Aster ®
Version
5.0
Titrate:
SDLL105 Tuyau subjected to sources of random fluid excitations
Date:
30/08/01
Author (S):
J. PIGAT Key
:
V2.02.105-B Page:
1/6

Organization (S): EDF/RNE/AMV

Handbook of Validation
V2.02 booklet: Linear dynamics of the beams
V2.02.105 document

SDLL105 - Tuyau subjected to sources
random fluid excitations

Summary:

A right piping embedded at an end in the wall of a tank and supporting a mass with the other
end is subjected to a fluid excitation.

The excitation is defined by its spectral concentration of power in the form of a “white vibration”.

It covers all the types of source established in the code:

·
source of flow-volume,
·
source of flow-mass,
·
source of pressure,
·
source of force,
·
imposed effort.

One is interested in the spectral concentration of power of the response in a degree of freedom of pressure located on
node supporting the mass.

The random dynamic response is given here moving absolute.
Handbook of Validation
V2.02 booklet: Linear dynamics of the beams
HT-62/01/012/A

Code_Aster ®
Version
5.0
Titrate:
SDLL105 Tuyau subjected to sources of random fluid excitations
Date:
30/08/01
Author (S):
J. PIGAT Key
:
V2.02.105-B Page:
2/6

1
Problem of reference

1.1 Geometry

4.0 m
6.0 m
acoustic section
section accoustics-mechanics
SOURCE
Tank
dx
m = 10 kg


Circular pipe of section:

External diameter: 0.1 m
Thickness: 3 mm

One does not take account of the field of gravity.

1.2
Material properties

Young modulus of the pipe:
E = 2.1 E+11 NR
Coefficient of compressibility of the pipe:
= 0.3
Density of the pipe:
= 7800 kg/m3
Density of the fluid:
F = 8.3 kg/m3
Celerity of the fluid:
C = 495 m/s

1.3
Boundary conditions and loadings

The DDL Dy, dz, drx, dry, drz are blocked for all the pipe.

On the acoustic section dx is also blocked and the only free DDL are PRES and PHI.

At the end on the side tank: PRES = 0. PHI = 0.
Handbook of Validation
V2.02 booklet: Linear dynamics of the beams
HT-62/01/012/A

Code_Aster ®
Version
5.0
Titrate:
SDLL105 Tuyau subjected to sources of random fluid excitations
Date:
30/08/01
Author (S):
J. PIGAT Key
:
V2.02.105-B Page:
3/6

2
Reference solution

2.1
Method of calculation used for the reference solution

No reference solution. The values tested for the not-regression are those obtained with
version 3.02.17.

2.2
Results of reference

Spectral concentration of power of the pressure to the node at the right end of the tube, the frequencies
10, 12, 14, 36, 38, 40 Hz. These frequencies are close to the two Eigen frequencies catches in
count (12.38 and 37.36 Hz).

2.3 References
bibliographical

[1]
C. DUVAL “Réponse dynamic under random excitations in Code_Aster: principles
theoretical and examples of use " - Note HP-61/92.148
Handbook of Validation
V2.02 booklet: Linear dynamics of the beams
HT-62/01/012/A

Code_Aster ®
Version
5.0
Titrate:
SDLL105 Tuyau subjected to sources of random fluid excitations
Date:
30/08/01
Author (S):
J. PIGAT Key
:
V2.02.105-B Page:
4/6

3 Modeling
With

3.1
Characteristics of modeling

4.0 m
6.0 m
dx
A7
A6
A5
A4
AM5 AM6 AM7 AM8 AM9 AM10
AM4
A3A2 A1 AM1AM2 AM3


Elements used for the pipes: FLUI_STRU

Element used for the mass in AM10: DIS_T

In all the calculation cases, the exiting spectral concentration is a white vibration of level 1.

The sources of flow-volume and flow-rate pressures are applied to node AM1.
The sources of mass and force are applied between nodes AM1 and AM2.

The last calculation case corresponds to a force imposed on node AM10 in the direction dx.

The clean modes of frequency in the interval [0, 100 Hz] were taken into account in calculation,
that is to say the first two modes.

Damping is introduced in modal form into the operator of dynamic response random.
For all the calculation cases, it is taken equal to 1%

3.2
Characteristics of the grid

A number of nodes: 17

A number of meshs and types: 16 SEG2, 1POI1

3.3 Functionalities
tested

Commands
MODE_ITER_SIMULT


CONSTANT DEFI_INTE_SPEC


DYNA_ALEA_MODAL EXCIT SIZE
:
“SOUR_DEBI_VOLU”

GRANDEUR
:
“SOUR_DEBI_MASS”

GRANDEUR
:
“SOUR_PRESS”

GRANDEUR
:
“SOUR_FORCE”

GRANDEUR
:
“EFFO”
REPONSE


REST_SPEC_PHYS



3.4 Remarks

The spectral concentrations of fluid source are expressed in their physical units. For a source
of volume flow rate in (m3/S) 2/Hz.
Handbook of Validation
V2.02 booklet: Linear dynamics of the beams
HT-62/01/012/A

Code_Aster ®
Version
5.0
Titrate:
SDLL105 Tuyau subjected to sources of random fluid excitations
Date:
30/08/01
Author (S):
J. PIGAT Key
:
V2.02.105-B Page:
5/6

4
Results of modeling A

4.1
Values of not-regression tested

Values of the spectral concentration of acceleration at point PB25:

Frequency
Type of source
Aster
10 Hz
SOUR_DEBI_VOLU
9.1954E+11
12 Hz
SOUR_DEBI_VOLU
4.3709E+13
14 Hz
SOUR_DEBI_VOLU
3.6428E+12
36 Hz
SOUR_DEBI_VOLU
1.1142E+13
38 Hz
SOUR_DEBI_VOLU
3.6976E+13
40 Hz
SOUR_DEBI_VOLU
2.6238E+12



10 Hz
SOUR_DEBI_MASS
1.3347E+10
12 Hz
SOUR_DEBI_MASS
6.3448E+11
14 Hz
SOUR_DEBI_MASS
5.2879E+10
36 Hz
SOUR_DEBI_MASS
1.6173E+11
38 Hz
SOUR_DEBI_MASS
5.3675E+11
40 Hz
SOUR_DEBI_MASS
3.8088E+10



10 Hz
SOUR_PRESS
9.5991E+00
12 Hz
SOUR_PRESS
2.5952E+02
14 Hz
SOUR_PRESS
1.2365E+01
36 Hz
SOUR_PRESS
3.2428E+00
38 Hz
SOUR_PRESS
1.3681E+01
40 Hz
SOUR_PRESS
1.1649E+00



10 Hz
SOUR_FORCE
1.9931E+05
12 Hz
SOUR_FORCE
5.3887E+06
14 Hz
SOUR_FORCE
2.5675E+05
36 Hz
SOUR_FORCE
6.7334E+04
38 Hz
SOUR_FORCE
2.8408E+05
40 Hz
SOUR_FORCE
2.4189E+04



10 Hz
EFFO
2.6542E03
12 Hz
EFFO
4.5780E02
14 Hz
EFFO
9.0980E04
36 Hz
EFFO
3.3472E02
38 Hz
EFFO
0.1186
40 Hz
EFFO
8.8587E03

4.2 Parameters
of execution

Version: STA 5.02
Machine: SGI-Origin 2000

System:
IRIX 64
Obstruction memory:
8 megawords
Time CPU To use:
3.21 seconds
Handbook of Validation
V2.02 booklet: Linear dynamics of the beams
HT-62/01/012/A

Code_Aster ®
Version
5.0
Titrate:
SDLL105 Tuyau subjected to sources of random fluid excitations
Date:
30/08/01
Author (S):
J. PIGAT Key
:
V2.02.105-B Page:
6/6

5
Summary of the results

This test makes it possible to pass in the options corresponding to the various types of source. It acts
primarily of a test developer.

Not having a reference solution, it is simply a question of not regressing between the versions.

Handbook of Validation
V2.02 booklet: Linear dynamics of the beams
HT-62/01/012/A

Outline document