Experimental investigation of harvesting stochastic vibration energy by a piezoelectric inverted beam with pendulum

We proposed a harvester composed of inverted piezoelectric beam and a pendulum to enhance the efficiency of vibration-based energy harvesting. Corresponding experiments were performed for validation. The amplitude-frequency response obtained in the vicinity of second natural frequency shows the feature of soften-spring type. The region of multiple solutions originated from nonlinearity could be extended when the excitation is increased to a high level. The experiment under stochastic excitation was carried out, and the corresponding responses were obtained. The absence of low frequency component in stochastic excitation was designed in excitation to show the first natural frequency component in response comes from the coupling between modes. The results verify the energy transformation phenomenon between the first two modes.