Abstract:

This paper summarizes development and testing of passive and active-passive heterogeneous blankets (HG) for the control of vibration and sound radiation from distributed structures such as beams and panels. Passive HG blankets consist of standard acoustic material such as foam into which numerous small masses have been embedded. The active version of the HG blankets utilize “active masses”. The results demonstrate that the passive HG blankets provide a significant increase in low frequency attenuation with only a small weight penalty. The active version of the HG blanket demonstrates an additional broadband performance increase over the passive version.