Optimization and Validation of Piezoelectric Cantilever Designs for Energy Harvesting from Bridge Vibrations

Abstract

This study proposes an optimization strategy for bridge applications with a vibration-based energy harvester design. Piezoelectric cantilevers with multiple degrees of freedom (DOF) are designed and optimized to match resonant frequencies with the vibration frequencies of a full-scale bridge structure under different loading conditions and measurement locations. The specific optimization procedures include bridge vibration acceleration measurement, simulation model development for estimating the resonant frequencies, a regression model for optimization of mass combinations, and final installation on the full-scale bridge for validation. The results show that the simulation model predicted the resonant frequencies of cantilevers with less than 1 Hz difference compared with laboratory measurements. Following the entire optimization procedures proposed in this study, the optimized 2-DOF and 3-DOF cantilevers were capable of generating 18.9 $\mu$ J and 23.4 $\mu$ J energy under one loading pass, respectively, which were significantly higher than those from the baseline designs. The feasibility of the proposed optimization strategy was demonstrated and validated for vibration-based energy harvesting from bridge structures.