A finite element model to analyze the dynamic characteristics of galloping based piezoelectric energy harvester

This paper proposes a novel finite element model (FEM) that can completely characterize the galloping based piezoelectric energy harvester (GPEH) systems. The challenges faced by conventional analytical models in explaining the complex nonlinear dynamics of GPEHs are completely resolved. The present system consists of a cantilever beam with two piezoelectric patches and a square prism attached at the end. A FEM code, in MATLAB environment, is developed to solve the proposed model, and the solutions are compared with the experimental and analytical results from the literature. The lateral galloping force coefficient is represented by a 7th order polynomial based on the quasi-steady theory ensuring highest precision (proved in literature). The results from the present model are found to be in a good agreement with the experimental values, and the accuracy is better compared to the analytical solutions at low wind speeds (<2.5 m/s). The position of maximum efficiency lies near to the onset speed of galloping (2-3 m/s) and the magnitude decreases with further increase in the wind speed. The present work emphasizes the importance of FE (numerical) solution over the conventional analytical ones, and hence will open a door to explore new numerical models in this area.