A new surface-damping concept with an active-passive hybrid constraining layer (HCL) is proposed to improve the damping performance of traditional active constrained layer (ACL) systems. Instead of using a pure piezoelectric constraining layer, passive and active materials are used together to constrain the viscoelastic material layer. A generic model of the HCL treatment is presented. Nondimensional equations of motion and boundary and connecting conditions are derived. The closed-form solutions to the equations are developed and analyzed. Tabletop tests are also performed to verify the feasibility of the new damping concept. It is shown that by properly selecting a passive constraining material and assigning appropriate lengths for the active and passive constraining parts, HCL can outperform a system with a pure active PZT coversheet, both in terms of its fail-safe ability and closed-loop damping performance. [S0739-3717(00)01503-8]

1.
Agnes, G., and Napolitano, K., 1993, “Active Constrained Layer Viscoelastic Damping,” Proceedings 34th SDM Conference, pp. 3499–3506.
2.
Baz, A., 1993, “Active Constrained Layer Damping,” Proceedings of Damping 93, San Francisco, CA., Vol. 3, pp. IBB 1–23.
3.
Shen, I. Y., 1993, “Intelligent Constrained Layer: An Innovative Approach,” Intelligent Structures, Materials, and Vibrations, ASME, DE-Vol. 58, pp. 75–82.
4.
Huang
,
S. C.
,
Inman
,
D. J.
, and
Austin
,
E. M.
,
1996
, “
Some Design Considerations for Active and Passive Constrained Layer Damping Treatments
,”
Smart Mater. Struct.
,
5
, pp.
301
313
.
5.
Liao
,
W. H.
, and
Wang
,
K. W.
,
1997
, “
On the Analysis of Viscoelastic Materials for Active Constrained Layer Damping Treatments
,”
J. Sound Vib.
,
207
, pp.
319
334
.
6.
Liao
,
W. H.
, and
Wang
,
K. W.
,
1997
, “
On the Active-Passive Hybrid Control Actions of Active Constrained Layers
,”
ASME J. Vibr. Acoust.
,
119
, pp.
563
572
.
7.
Liao
,
W. H.
, and
Wang
,
K. W.
,
1996
, “
A New Active Constrained Layer Configuration with Enhanced Boundary Actions
,”
Smart Mater. Struct.
,
5
, pp.
638
648
.
8.
Liao
,
W. H.
, and
Wang
,
K. W.
,
1998
, “
Characteristics of Enhanced Active Constrained Layer Damping Treatments with Edge Elements, Part 2: System Analysis
,”
ASME J. Vibr. Acoust.
,
120
, pp.
894
900
.
9.
Liu
,
Y.
, and
Wang
,
K. W.
,
1999
, “
A Non-dimensional Parametric Study of Enhanced Active Constrained Layer Damping Treatments
,”
J. Sound Vib.
,
223
, No.
4
, pp.
611
644
.
10.
Lam, M. J., Inman, D. J., and Saunders, W. R., 1998, “Variations of Hybrid Damping,” Proceedings of SPIE on Smart Structures and Materials, Vol. 3327, pp. 32–43.
11.
Dosch
,
J. J.
,
Inman
,
D. J.
, and
Garcia
,
E.
,
1992
, “
A Self-Sensing Piezoelectric Actuator for Collocated Control
,”
J. Intel. Syst. Struct.
,
3
, pp.
166
185
.
12.
Shen
,
I. Y.
,
1997
, “
A Variational Formulation, a Work-Energy Relation and Damping Mechanisms of Active Constrained Layer Treatments
,”
ASME J. Vibr. Acoust.
,
119
, pp.
192
199
.
13.
Baz
,
A.
,
1997
, “
Optimization of Energy Dissipation Characteristics of Active Constrained Layer Damping
,”
Smart Mater. Struct.
,
6
, pp.
360
368
.
14.
Plunkett
,
R.
, and
Lee
,
C. T.
,
1970
, “
Length Optimization for Constrained Viscoelastic Layer Damping
,”
J. Acoust. Soc. Am.
,
48
, No.
1
, Part 2,
150
161
.
15.
Anderson
,
E. H.
, and
Hagood
,
N. W.
,
1994
, “
Simultaneous Piezoelectric Sensing/Actuation: Analysis and Application to Controlled Structures
,”
J. Sound Vib.
,
174
, No.
5
, pp.
617
639
.
16.
Inman, D. J., 1994, Engineering Vibration, Prentice Hall.
You do not currently have access to this content.