Experimental nonlinear dynamic regimes for energy harvesting from cantilever bistable shells

An experimental campaign on a cantilever composite bistable shell with a piezoelectric patch is reported in the paper. The considered shell is characterized by two stable configurations far apart in terms of natural frequencies and geometries. Harmonic forcing is applied at the shell's clamped side through an electrodynamic shaker and the dynamic response is measured through an embedded strain gauge. Different dynamic regimes are encountered by performing excitation frequency and amplitude sweeps. The resonance scenarios around the two natural frequencies corresponding to the stable configurations show different softening behavior. The excitation amplitude threshold level for snap-through motion is identified. Experimental power generation maps plotted on the excitation frequency–amplitude plane are created to provide useful design insights for vibration energy harvesting purposes.