Conventional Passive Constrained Layer Damping (PCLD) treatments with viscoelastic cores are provided with built-in sensing and actuation capabilities to actively control and enhance their vibration damping characteristics. The design parameters and control gains of the resulting Active Constrained Layer Damping (ACLD) treatments are optimally selected, in this paper, for fully-treated beams using rational design procedures. The optimal thickness and shear modulus of the passive visco-elastic core are determined first to maximize the modal damping ratios and minimize the total weight of the damping treatment. The control gains of the ACLD are then selected using optimal control theory to minimize a weighted sum of the vibrational and control energies. The theoretical performance of beams treated with the optimally selected ACLD treatment is determined at different excitation frequencies and operating temperatures. Comparisons are made with the performance of beams treated with optimal PCLD treatments and untreated beams which are controlled only by conventional Active Controllers (AC). The results obtained emphasize the potential of the optimally designed ACLD as an effective means for providing broad-band attenuation capabilities over wide range or operating temperatures as compared to PCLD treatments.

1.
Agnes, G. S., and Napolitano, K., 1993, “Active Constrained Layer Viscoelastic Damping,” Proc. of 34th SDM Conference, pp. 3499–3506, April.
2.
Azvine, B., Tomlinson, G., and Wynne, R., 1994, “Initial Studies into the Use of Active Contrained-Layer Damping for Controlling Resonant Vibrations,” Proc. of Smart Structures and Materials Conference on Passive Damping, C. Johnson, ed; Vol. 2193, pp. 138–149, Orlando, FL.
3.
Bailey
T
, and
Hubbard
J.
, “
Distributed Piezo-electric Polymer Active Vibration Control of a Cantilever Beam
,”
Journal of Guidance and Control
, Vol.
8
, pp.
606
611
.
4.
Baz, A., and Poh, S., 1995, “Optimal Vibration Control with Modal Positive Position Feedback,” J. of Optimal Control: Applications & Methods, in press.
5.
Baz, A., 1993a, “Active Constrained Layer Damping,” U.S. patent application.
6.
Baz, A., 1993b, “Active Constrained Layer Damping,” DAMPING’93 Conference, San Francisco, CA, pp. IBB 1–23.
7.
Baz, A., and Ro, J., 1993a, “Partial Treatment of Flexible Beams with Active Constrained Layer Damping,” Conference of Engineering Sciences Society, ASME-AMD-Vol. 167, pp. 61–80, Charlottesville, VA, June.
8.
Baz, A., and Ro, J., 1993b, “Finite Element Modeling and Performance of Active Constrained Layer Damping,” Ninth VPI & SU Conference on Dynamics & Control of Large Structures, pp. 345–358, Blacksburg, VA, May.
9.
Baz, A., and Ro, J., 1993c, “Vibration Control of Rotating Beams with Active Constrained Layer Damping,” First Workshop on Smart Structures, Univ. of Texas, Arlington, Sept. 1993c.
10.
Baz
A.
, and
Ro
J.
, “
Actively-Controlled Constrained Layer Damping
,”
Sound and Vibration Magazine
, Vol.
28
, No.
3
, pp.
18
21
, March.
11.
Baz, A., and Ro, J., 1995, “Performance Characteristics of Active Constrained Layer Damping,” Shock and Vibration Journal, in press.
12.
Crawley
E.
, and
De Luis
J.
, “
Use of Piezoelectric Actuators as Elements in Intelligent Structures
,”
Journal of AIAA
, Vol.
25
, No.
10
, pp.
1373
1385
.
13.
Cremer, L., Heckel, M., and Ungar, E., 1988 Structure-Borne Sound: Structural Vibrations and Sound Radiation at Audio Frequencies, Second edition, Springer-Verlag, Berlin.
14.
Edberg, D., and Biscos, A., “Design and Development of Passive and Active Damping Concepts for Adaptive Structures,” Conference on Active Materials and Adaptive Structures, G. Knowles, ed., IOP Publishing Ltd., Bristol, UK, pp. 377–382.
15.
Gibson, W., and Johnson, C, “Optimization Methods for Design of Viscoelastic Damping Treatments,” The Role of Damping in Vibration and Noise Control, L. Rogers and J. C. Simonis, eds., ASME DE-Vol. 5, pp. 143–149.
16.
Jameson
A.
, “
Optimization of Linear Systems of Constrained Configuration
,”
Intl. J. of Control
, Vol.
11
, No.
3
, pp.
409
421
.
17.
Kodiyamalam, S., and Molnar, J., 1992, “Optimization of Constrained Viscoelastic Damping Treatments for Passive Vibration Control,” AIAA paper # 92-2269-CP.
18.
Lewis, F. L., 1992, Applied Optimal Control and Estimation, Prentice-Hall, Inc., Englewood Cliffs, NJ.
19.
Lifshitz
J. M.
, and
Leibowitz
M.
,
1987
, “
Optimal Sandwich Beam Design for Maximum Viscoelastic Damping
,”
Int. J. of Solids & Structures
, Vol.
23
, No.
7
, pp.
1027
1034
.
20.
Marcelin
J.-L.
,
Trompette
Ph.
, and
Smati
A.
,
1992
, “
Optimal Constrained Layer Damping with Partial Coverage
,”
Finite Elements in Analysis and Design
, Vol.
12
, pp.
273
280
.
21.
Miller, S., and Hubbard, Jr., J., 1987, “Observability of a Bernoulli-Euler Beam using PVF2 as a Distributed Sensor,” Seventh Conference on Dynamics & Control of Large Structures, VPI & SU, Blacksburg, VA., pp. 375–930, May.
22.
Nashif, A., Jones, D., and Henderson, J., 1985, “Vibration Damping, John Wiley & Sons, New York.
23.
Plump, J., and Hubbard, J. E., “Modeling of An Active Constrained Layer Damper,” Twelves Intl. Congress on Acoustics, Paper # D41, Toronto Canada, July 24–31.
24.
Plunkett
R.
, and
Lee
C. T.
,
1970
, “
Length Optimization of Constrained Viscoelastic Layer Damping
,”
J. of Acoustical Society of America
, Vol.
48
, No.
1
, pp.
150
161
.
25.
Raju Mantena
P.
,
Gibson
R.
, and
Hwang
S.
,
1991
, “
Optimal Constrained Viscoelastic Tape Lengths for Maximizing Damping in Laminated Composites
,”
J. of AIAA
, Vol.
29
, No.
10
, pp.
1678
1685
.
26.
Rao
D. K.
, “
Frequency and Loss Factors of Sandwich Beams under Various Boundary Conditions
,”
J. of Mechanical Engrg. Science IMECH
, Vol.
20
, No.
5
, pp.
271
282
.
27.
Rao, S. S., 1987, Optimization Theory and Applications, 2nd edition, John Wiley and Sons, New York.
28.
Shen
I. Y.
,
1994
, “
Hybrid Damping Through Intelligent Constrained Layer Treatments
,”
ASME Journal of Vibration and Acoustics
, Vol.
116
, No.
3
, pp.
341
349
.
29.
Van Nostrand, W., Knowles, G., and Inman, D., 1994, “Finite Element Modeling for Active Constrained-Layer Damping,” Proc. of Smart Structures and Materials Conference on Passive Damping, C. Johnson, ed., Vol. 2193, pp. 126–137, Orlando, FL.
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