Advanced concepts in nonlinear piezoelectric energy harvesting: Intentionally designed, inherently present, and circuit nonlinearities

Abstract

This work is centered on the modeling, experimental identification, and dynamic interaction of inherently present and intentionally designed nonlinearities of piezoelectric structures focusing on applications to vibration energy harvesting. The following topics are explored in this theoretical and experimental research: (1) frequency bandwidth enhancement using a simple, intentionally designed, geometrically nonlinear M-shaped oscillator for low-intensity base accelerations; (2) multi-term harmonic balance analysis of this structure for primary and secondary resonance behaviors when coupled with piezoelectrics and an electrical load; (3) inherent electroelastic material softening and dissipative nonlinearities for various piezoelectric materials with a dynamical systems approach; and (4) development of a complete approximate analytical multiphysics electroelastic modeling framework accounting for material, dissipative, and strong circuit nonlinearities. The ramifications of this research extend beyond energy harvesting, since inherent nonlinearities of piezoelectric materials are pronounced in various applications including sensing, actuation, and vibration control, which can also benefit from bandwidth enhancement from designed nonlinearities.