Multimodal shunt damping of monolithic bladed drums using multiple digital vibration absorbers

Based on a digital realization of piezoelectric shunt circuits, this works presents a proof-of-concept damping approach tailored to address the complex dynamics of monolithic bladed drums (BluMs) and attenuate their vibrations. This approach comprises the simultaneous use of multiple digital vibration absorbers (DVAs) together with a mean shunt strategy, taking advantage of the fact that multiple absorbers act simultaneously on the structure and that the blade modes of BluMs appear closely-spaced. In order to target multiple groups of modes, this strategy is incorporated in a multi-staged shunt circuit. The damping concept is numerically and experimentally demonstrated on a BluM with multiple piezoelectric patches, proving its ability to achieve excellent damping performance on multiple groups of modes. This performance is shown to be relatively insensitive to the spatial distribution of the shunted patches. Based on a robustness study, it was also found that the shunts are robust to changes in the host structure which could, e.g., be due to mistuning. Owing their digital nature, DVAs are easily adjustable making them highly attractive in practical applications.