The problem of flexible structure vibration isolation on a flexible foundation is analytically investigated by simplifying the vibration isolation as single axis isolation, which can be realized by a proper design, and the problem of the whole spacecraft vibration is taken as an example for the application as both the spacecraft (isolated structure) and the launch vehicle (foundation) are flexible structures. A numerical example of the whole spacecraft vibration isolation is also provided for further explaining those conclusions derived from the analytical studies. It is found from the study that the isolator’s damping is important for attenuating the vibration and that weakening the isolator’s stiffness has the same effect as increasing its damping. However, a weaker stiffness means a weaker coupling among the structures and may magnify the vibration at some resonant frequencies, which are close to those of individual structures. The coupling effect of the structure’s flexibility on the isolation may be significant in some cases and a coupling analysis is essential for ensuring the isolation performance. Because of the importance of the isolator’s damping in reducing the vibration transmissibility and the vibration of the coupled structure, it is more appropriate to describe the vibration isolation of the flexible structure as vibration attenuation.

1.
Sciulli
,
D.
, and
Inman
,
D. J.
, 1998, “
Isolation Design for a Flexible System
,”
J. Sound Vib.
0022-460X,
216
(
2
), pp.
251
267
.
2.
Sciulli
,
D.
, 1997, “
Dynamics and Control for Vibration Isolation Design
,” Ph.D. thesis, Virginia Polytechnic Institute and State University, Blacksburg, VA.
3.
Soliman
,
J. I.
, and
Hallam
,
M. G.
, 1968, “
Vibration Isolation Between Non-Rigid Machines and Non-Rigid Foundations
,”
J. Sound Vib.
,
8
(
2
), pp.
329
351
. 0022-460X
4.
Warburton
,
G. B.
, 1973, “
Reduction of the Vibration Response of Complex Structures
,”
Isolation of Mechanical Vibration, Impact and Noise
,
J. C.
Snowdon
and
E. E.
Ungar
, eds.,
ASME
,
New York
, pp.
1
34
.
5.
Tu
,
Y. Q.
, and
Zheng
,
G. T.
, 2007, “
On the Vibration Isolation of Flexible Structures
,”
ASME J. Appl. Mech.
0021-8936,
74
(
3
), pp.
415
420
.
6.
Kaul
,
S.
,
Dhingra
,
A. K.
, and
Hunter
,
T. G.
, 2007, “
Frame Flexibility Effects on Engine Mount Optimization for Vibration Isolation in Motorcycles
,”
ASME J. Vibr. Acoust.
0739-3717,
129
(
5
), pp.
590
600
.
7.
Johnson
,
C. D.
,
Wilke
,
P. S.
, and
Pendleton
,
S. C.
, 2006, “
SoftRide Vibration and Shock Isolation Systems That Protect Spacecraft From Launch Dynamic Environments
,”
Proceedings of the 38th Aerospace Mechanisms Symposium
, Langley Research Center.
8.
Liu
,
L. K.
,
Liang
,
L.
,
Zheng
,
G. T.
, and
Huang
,
W. H.
, 2005, “
Dynamic Design of Octo-Strut Platform for Launch Stage Whole-Spacecraft Vibration Isolation
,”
J. Spacecr. Rockets
0022-4650,
42
(
4
), pp.
654
662
.
9.
Winthrop
,
M. F.
, and
Cobb
,
R. G.
, 2003, “
Survey of State-of-the-Art Vibration Isolation Research and Technology for Space Applications
,”
Proc. SPIE
,
5052
, pp.
13
26
. 0277-786X
10.
Zheng
,
G. T.
, 2003, “
Parameter Studies of the Whole Spacecraft Vibration Isolation
,”
AIAA J.
,
41
(
9
), pp.
1839
1841
. 0001-1452
11.
Zheng
,
G. T.
,
Liu
,
L. K.
,
Liang
,
L.
, and
He
,
L.
, 2006, “
Uncoupled Vibration Attenuation/Isolation Devices
,” US Patent Application Serial No. 11/601,547.
This content is only available via PDF.
You do not currently have access to this content.