Hybrid time-domain and spatial filtering nonlinear damping strategy for efficient broadband vibration control

Limiting low-frequency vibrations with low-energy, yet efficient strategies is of prior importance in embedded devices, such as on-board electronics. Hence, particular attention has been paid over the few last decades to electromechanical materials able to convert mechanical energy into electricity, therefore reducing the mechanical energy within the structure yielding a damping effect. However, under multimodal or more generally broadband vibration spectra, the performance of such systems is compromised. Hence, the purpose of this paper is to expose an efficient nonlinear technique based on the intermittent voltage inversion of a piezoelectric element voltage through switching actions. In order to achieve very good performance under broadband vibrations, spatial and time domain filtering approaches are implemented within the control of the digital switches, allowing simultaneous mode separation thanks to the spatial filtering process and better energy transfer due to the processing of the time history of the signal. Finite-element simulations, based on an experimental device, show that such a hybrid technique significantly outperforms the classical switching algorithm as well as the spatial and time domain approaches (when taken separately).