Enhancing the Performance of Constrained Layer Damping by Confining Vibrational Energy

Abstract

A feasibility study was conducted to demonstrate that the combination of Constrained Layer Damping (CLD) and Vibration Control by Confinement (VCC) is an effective and viable approach to today’s noise and vibration problems. The objective of this paper is to report on the degree of improvement of CLD when used in conjunction with VCC. Two panel-type structures, resembling a simplified model of the panel section of a car door, are examined. The entire upper surface of the first panel was covered by CLD. On the other hand, only 63% of the second panel is covered by CLD. A confining rib was added to the second panel to localize the vibrational energy to the remaining 37% of its surface over which no CLD was added. The finite element method was employed to model both structures and generate the numerical results presented in this article. Four equally distributed points were identified to excite and measure the response. The plate was subjected to transient and harmonic excitations. Our preliminary results clearly show that not only VCC can be used as a stand-alone mechanism to suppress or isolate vibrations but also can be combined with CLD to significantly improve performance. Furthermore, additional ramifications of the VCC approach as they apply to passive or active vibration control systems are discussed.