Structural vibration control via R-L shunted active fiber composites

This article presents a successful extension of passive R-L shunt damping to piezoelectric ceramic elements working in direct 3-3 mode and a performance comparison to elements working in indirect 3-1 mode. A new circuit topology is implemented to synthesize the very large inductances required by the low inherent piezoelectric device capacitance at relatively low frequencies. This allows for efficient tuning of the R-L circuit to the structure resonance frequency to be damped. The vibration suppression performance of monolithic piezoelectric ceramic actuators and active fiber composites is compared in this study. For this purpose, different actuators are bonded on aluminum cantilever plates. An integrated FE model is implemented for the prediction of structure resonance frequencies, optimum values for electric components, and the resulting vibration suppression performance. The passive structure, bonded active patch, and shunted electrical network are analyzed within the same FE model. Active fiber composite patches working in the direct 3-3 mode show equivalent specific damping performance compared to conventional monolithic 3-1 actuated patches. Issues related to the sensitivity of R-L shunts to variations in environmental and operational conditions are discussed in this study. In short, monolithic actuators operating on the 3-1 piezoelectric effect seem to be the best for use in R-L shunting.