Code_Aster
®
Version
4.0
Titrate:
SDLD25 Système mass-arises with viscous shock absorber
Date:
05/01/98
Author (S):
P. GUIHOT
Key:
V2.01.025-B
Page:
1/6
Manual of Validation
V2.01 booklet: Linear dynamics of the discrete systems
HP-52/96/042 - Ind A
Organization (S):
EDF/EP/AMV
Manual of Validation
V2.01 booklet: Linear dynamics of the discrete systems
V2.01.025 document
SDLD25 - System mass-arises with shock absorber
viscous proportional (spectral answer)
Summary
This one-way problem consists in carrying out a spectral seismic analysis of a mechanical structure
composed of a whole of mass-springs with viscous shock absorbers subjected to a seismic stress
provided in the shape of a spectrum of response of pseudo oscillators in acceleration.
Via this problem, one tests modal combination SRSS of the operator
COMB_SISM_MODAL
[U4.54.04]. In addition, several operators of preprocessing are tested;
DEFI_FONCTION
and
DEFI_NAPPE
.
The results obtained are in concord with the results of guide VPCS.
This test is also a test of resorption of LICE. There are no differences between the ASTER results and them
LICE results.
Code_Aster
®
Version
4.0
Titrate:
SDLD25 Système mass-arises with viscous shock absorber
Date:
05/01/98
Author (S):
P. GUIHOT
Key:
V2.01.025-B
Page:
2/6
Manual of Validation
V2.01 booklet: Linear dynamics of the discrete systems
HP-52/96/042 - Ind A
1
Problem of reference
1.1 Geometry
X, U
P1
U1
With
C
m
C
K
K
m
P2
U2
m
C
K
P3
U3
m
C
K
P8
B
U8
Specific masses:
m
P1
= m
P2
= m
P3
= ...... = m
P8
= m
Stiffnesses of connection:
K
AP1
= K
P1P2
= K
P2P3
= ...... = K
P8B
= K
Viscous depreciation:
C
AP1
= C
P1P2
= C
P2P3
= ...... = C
P8B
= C
1.2
Material properties
Comes out from linear elastic translation
K =
10
5
NR/m
Specific mass
m =
10 kg
One-way viscous damping
C =
50 NR/(m/s)
1.3
Boundary conditions and loadings
Not A and b: embedded (U = 0)
Spectrum of acceleration to the supports
Ý
Ý
U
(F, has) normalized to 1. ms
2
Points A and b:
Ý
Ý
U
=
Ý
Ý
U
(F, has)
3
1
25
ms
2
13
33
10
1
5%
0.5%
frequency (Hz)
Code_Aster
®
Version
4.0
Titrate:
SDLD25 Système mass-arises with viscous shock absorber
Date:
05/01/98
Author (S):
P. GUIHOT
Key:
V2.01.025-B
Page:
3/6
Manual of Validation
V2.01 booklet: Linear dynamics of the discrete systems
HP-52/96/042 - Ind A
2
Reference solution
2.1
Method of calculation used for the reference solution
Comparison with other codes.
Guide VPCS: test in preparation.
2.2
Results of reference
Absolute acceleration according to X at the points A, P1, P2, P3, P4.
2.3 References
bibliographical
[1]
Guide VPCS: Second edition to be appeared.
[2]
J. PIRANDA: Note of use of the software of modal analysis MODAN - Version 0.2.
Laboratory of Mechanics Applied - University of Frank County Besancon (1990).
Code_Aster
®
Version
4.0
Titrate:
SDLD25 Système mass-arises with viscous shock absorber
Date:
05/01/98
Author (S):
P. GUIHOT
Key:
V2.01.025-B
Page:
4/6
Manual of Validation
V2.01 booklet: Linear dynamics of the discrete systems
HP-52/96/042 - Ind A
3 Modeling
With
3.1
Characteristics of modeling
With
B
P
1
y
X
P
2
P
3
P
4
P
5
P
6
P
7
P
8
Characteristics of the elements:
DISCRETE
:
with nodal masses
M_T_D_N
and matrices of rigidity
K_T_D_L
and matrices of damping
A_T_D_L
Limiting conditions:
in all the nodes
DDL_IMPO:
(ALL:“YES” DY: 0. , DZ: 0. )
with the nodes ends
(GROUP_NO: AB DX: 0. )
Names of the nodes:
Not A = N1
P
1
= N2
Not B = N10
P
2
= N3
.............
P
8
= N9
3.2
Characteristics of the mesh
A number of nodes: 10
A number of meshs and types: 9
SEG2
3.3 Functionalities
tested
Controls
Keys
AFFE_MODELE
ALL
“MECHANICAL”
“DIS_T'
[U4.22.01]
GROUP_NO
“DIS_T'
AFFE_CARA_ELEM
DISCRETE
GROUP_MA
“K_T_D_L'
[U4.24.01]
GROUP_MA
“A_T_D_L'
GROUP_NO
“M_T_D_N'
COMB_SISM_MODAL
[U4.54.04]
Code_Aster
®
Version
4.0
Titrate:
SDLD25 Système mass-arises with viscous shock absorber
Date:
05/01/98
Author (S):
P. GUIHOT
Key:
V2.01.025-B
Page:
5/6
Manual of Validation
V2.01 booklet: Linear dynamics of the discrete systems
HP-52/96/042 - Ind A
4
Results of modeling A
4.1 Values
tested
Identification
Reference
Aster
% difference
Eigen frequencies
1
5.53
5.527
- 0.04
2
10.89
10.886
- 0.02
3
15.92
15.915
- 0.02
4
20.46
20.460
0.00
5
24.38
24.383
0.01
6
27.57
27.566
- 0.01
7
29.91
29.911
0.00
8
31.35
31.347
- 0.01
Size localization
ACCE_ABSOLU A DX
1.0
1.0
1.0
P1 DX
10.69
10.45
2.24
P2 DX
19.26
19.03
1.19
P3 DX
25.46
25.32
0.55
P4 DX
29.16
28.95
0.73
4.2 Remarks
Mode
1
2
3
4
5
6
7
8
Damping (in %)
0.868
1.710
2.500
3.213
3.830
4.331
4.698
4.924
Spectrum
23.19
19.54
9.033
3.928
2.282
1.601
1.283
1.136
4.3 Parameters
of execution
Version: 3.05.02
Machine: CRAY
System: UNICOS 8.0
Overall dimension memory: 8 megawords
Time CPU To use: 5.75 seconds
Code_Aster
®
Version
4.0
Titrate:
SDLD25 Système mass-arises with viscous shock absorber
Date:
05/01/98
Author (S):
P. GUIHOT
Key:
V2.01.025-B
Page:
6/6
Manual of Validation
V2.01 booklet: Linear dynamics of the discrete systems
HP-52/96/042 - Ind A
5
Summary of the results
One obtains a good agreement between the solution
Aster
and the reference solution which comes from other codes.
Results
Aster
are identical to the LICE results until the second decimal.