Vibration attenuation in a nonlinear flexible structure via nonlinear switching circuits and energy harvesting implications

We study the suppression of strongly nonlinear vibrations of a flexible structure by using nonlinear switching circuit techniques, namely the synchronized switch damping on short circuit and the synchronized switch damping on inductor circuit, as well as energy harvesting implications through the synchronized switch harvesting on inductor circuit combined with the same nonlinear structure. Nonlinear switching shunts have been mostly explored for suppressing linear resonance in flexible structures. However, such flexible structures can easily undergo undesired resonant bifurcations and exhibit co-existing large- and small-amplitude branches in their frequency response. In this work, we investigate a strongly nonlinear and weakly coupled flexible structure for suppressing its large-amplitude periodic response branch under primary resonance excitation. The synchronized switch damping on short circuit and synchronized switch damping on inductor circuit damping techniques are employed and compared with the baseline (near short circuit) frequency response. It is shown that the synchronized switch damping on inductor circuit can substantially reduce the large-amplitude branch, offering the possibility of entirely suppressing undesired bifurcations. Energy harvesting implications are also explored by using the same structure as a wideband energy harvester. While the harvested power can be boosted with a synchronized switch harvesting on inductor circuit, the large-amplitude branch of the harvester is significantly shortened due to the strong shunt damping effect as a trade-off.