Nonlinear Multi-Scale Dynamics Modeling of a Piezoelectric Energy Harvester

Hysteretic effects play a crucial role in the behavior of devices based on piezoelectric materials. Most of the research focuses on modeling these effects for controlling the dynamic response of piezoelectric actuators. Few studies discuss how hysteresis influences power generation and performances of energy harvesters based on such active materials. In this paper, a recently developed physics-based model of a PZT crystal is employed to assess the effects of material mesoscopic variables on the macroscopic response of a piezoelectric energy harvester modeled as a SDOF system. A multi-scale approach is adopted where, at the mesoscale, crystal domain switching - the source of hysteretic behavior - is taken into account through a probabilistic thermodynamic approach. Effects of hysteretic nonlinearities on harvesting performances of the considered device are investigated by means of simulations. A comparison between predictions of two models - with and without hysteresis - is also reported.