Analysis of a friction-induced vibration piezoelectric energy generator under linear, bi-linear, and impact conditions

The mismatch in natural frequencies between the piezoelectric energy generator and the energy source affects its energy generation performance. In this research, a novel piezoelectric energy generator with linear, bi-linear, and impact design configurations is proposed. The energy generator utilizes friction as excitation to achieve self-exciting friction-induced vibration (FIV) close to the systems’ resonant frequencies for piezoelectric energy generation. The dynamic response under FIV is described by a mathematical model incorporating the piezoelectric coupling effect. The energy generation from piezoelectric material is evaluated by simulating the charging process of a capacitor using an iterative method. The reliability of the model and the stable high-frequency FIV phenomenon with linear, bi-linear, and impact design configurations are validated by experiment. Furthermore, parameter studies are conducted to investigate their effect on the efficiency and effectiveness of energy generation. With a normal load FN = 30 N and an initial sliding velocity v0 = 0.542 m/s, the linear, bi-linear, and impact design configurations yield peak-to-peak voltages of approximately 2.9 V, 3.8 V, and 20.6 V, respectively. Higher voltages can be generated under optimal operating conditions. The proposed energy generator can be integrated into rotating or sliding equipment to harness the energy derived from FIV. Enhanced energy generation performance can be achieved by modifying structural design and incorporating materials with better properties. The current study paves the way for piezoelectric energy generation using FIV and explores the potential of utilizing dynamic frictional signals in sensing and structural health monitoring scenarios.