Perforated Damping Treatment; A Novel Approach to Reduction of Weight 1999-01-1679

In noise and vibration control, damping treatments are applied on panel surfaces to dissipate the energy of flexural vibrations. Presence of damping treatment on the surface of a panel also plays an important role in the resulting vibro-acoustic characteristics of the composite system. The focus of this study is to explore possibilities of reducing the weight of damping treatments by means of perforation without sacrificing performance. The power injection concept from Statistical Energy Analysis (SEA) is used in conjunction with Finite Element Analysis (FEA) to predict the effect of perforated unconstrained layer treatments on flat rectangular panels. Normalized radiated sound power of the treated panels are calculated to assess the effect of varying percentage of perforation on structural-acoustic coupling. The results indicate that it is possible to remove almost 50% of the treatment and still maintain an acceptable level of vibro-acoustic performance in the structure, depending on the thickness of the treatment and perforation pattern.