Numerical Investigations into the Effects of Multiple Parameters on Nonlinear Piezoelectric Vibration Energy Harvesters

It is very promising to improve the performance of piezoelectric vibration energy harvesters (PVEHs) using nonlinearities in energy harvesting applications. However it is almost impossible to analytically obtain their nonlinear dynamic behaviors. The goal of this paper is to investigate the relations among power outputs, vibration characteristics, and systematic nonlinearities by numerical analysis. A mathematical model of nonlinear PVEH is built by combining nonlinear damping, stiffness, and piezoelectric coupling coefficient. An iterative algorithm is proposed to solve the nonlinear model. Then the effects of these nonlinear parameters on the performance of the PVEH are studied deeply. The results demonstrate that the power output of a nonlinear PVEH will be overestimated or subestimated using a linear model. And nonlinearities can be used for broadband and low frequency vibration energy harvesting.