Structural vibration damping experiments using improved piezoelectric shunts

The theoretical analysis of an improved piezoelectric shunt using a piezoelectric PZT element shunted with a parallel resistor and inductor circuit for passive structural damping and vibration control was studied(1). In this paper, we will report results of the experiments of the improved shunting technique which were performed and demonstrated successfully for passive vibration control in the ARPA consortium SPICES program on several structures including thermoset fiberglass/epoxy composite plates with embedded PZT patches and cantilever beams with surface bonded patches. Vibration reductions on resonant response of more than 17 dB using the single mode shunting have been obtained on an 18'' x 18'' x 0.5'' composite plate with eight embedded PZT patches. When we excite another composite plate with a commercial compressor mounted on top of it and rum on the shunt circuits, the transmitted vibration level measured with a force gauge at a plate mounting post is reduced about 15 dB. The improved piezoelectric shunting technique has been studied further to shunt-damp multiple vibration modes using only a single PZT patch. The experimental result of the multiple mode shunting will also be presented.