Vibration Damping of Structures Using Active Constrained Layer Damping

2018 ◽  
pp. 301-360
2001 ◽  
Author(s):  
Arnold Lumsdaine

Abstract Active Constrained Layer Damping (ACLD), involving a hybrid of active and passive damping elements, has been shown to be a promising method for maximizing vibration damping effectiveness. Active damping can be effective at reducing vibration of a given single mode. Passive damping has dissipative qualities for all modes. There has been much discussion comparing and contrasting the uses of these different methods in the literature. It has been found that using a hybrid ACLD layer can be more effective than just using an active control (AC) approach or a Passive Constrained Layer Damper (PCLD) approach, in some cases. ACLD structures are characterized in the literature either by the development of analytic equations, or by finite element modeling. In cases where the ACLD structure is modeled using finite elements, the formulation is done by the author in developing a code. This limits the availability of the result beyond a specific application. For the modeling of ACLD structures to be more generally applicable, and available, modeling could be done using a commercial finite element code. A greater variety of different structures could be modeled, and structural optimization could easily be integrated. The study of ACLD structures would be available to an audience without the resources to construct their own elements. To the author’s knowledge, no studies of ACLD structures exist using a generally available finite element code. The ABAQUS commercial finite element code, with certain customizations, is used in this study. Results compare favorably with other sources in the literature.


2002 ◽  
Vol 8 (6) ◽  
pp. 877-902 ◽  
Author(s):  
W. Laplante ◽  
T. Chen ◽  
A. Baz ◽  
W. Sheilds

Vibration and sound radiation from fluid-loaded cylindrical shells are controlled using patches of Active Constrained Layer Damping (ACLD). The performance and the enhanced damping characteristics via reduced vibrations and sound radiation in the surrounding fluid is demonstrated both theoretically and experimentally. A prime motivation for this work is the potential wide applications in submarines and torpedoes where acoustic stealth is critical to the effectiveness of missions. A finite element model is also developed to predict the vibration and the acoustic radiation in the surrounding fluid of the ACLD-treated cylinders. The developed model is used to study the effectiveness of the control and placement strategies of the ACLD in controlling the fluid-structure interactions. A water tank is constructed that incorporates test cylinders treated with two ACLD patches placed for targeting specific vibration modes. Using this arrangement, the effectiveness of different control strategies is studied when the submerged cylinders are subjected to internal excitation, and the radiated sound pressure level in the water is observed. Comparisons are made between the experimental results and the theoretical predictions to validate the finite element model.


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