Nondimensional model and parametric studies of impact piezoelectric energy harvesting with dissipation

Impact piezoelectric energy harvesting could overcome the frequency matching problem of resonant energy harvesters and achieve broadband performance. However, the mechanism of impact dissipation in impact piezoelectric energy harvesting has not been investigated. No comprehensive model is available being able to analyze the response of impact piezoelectric energy harvesters under different impact velocities. This paper is aimed at developing a comprehensive model of impact piezoelectric energy harvesting by considering impact dissipation mechanism and conducting experiments to validate the developed model. In this paper, the electromechanical model, Hertzian contact theory and Hunt-Crossley model of impact dissipation are considered as constitutive mechanisms. The developed model is analyzed in terms of impact force and energy distribution. A testing method is proposed to investigate the impact piezoelectric energy harvester with a high-speed camera. The developed model is experimentally validated that it well predicts the response of impact piezoelectric energy harvesters by considering impact dissipation mechanism. The dimensionless model is achieved and the implications of mass ratio and impact dissipation on dynamics of the whole system is newly discovered. The guideline for improving harvested energy is proposed based on the results of parametric studies.