Effects of Bluff Body Cross-Section on the Electrical Response of a Piezoelectric Energy Harvester Under Hybrid Excitation

To enhance the energy harvesting efficiency of piezoelectric energy harvesters, this study focuses on comprehensively analyzing the electrical response characteristics of piezoelectric energy harvesters with different bluff body cross-sections under hybrid excitation. Firstly, the forced vibration equation of the piezoelectric beam is derived by employing the Euler–Bernoulli beam bending vibration theory. Subsequently, an electromechanical coupling model of the piezoelectric laminated beam is established, allowing for a comprehensive understanding of the system's behavior. The piezoelectric beam is then simplified into a single-degree-of-freedom system using the Galerkin method, and the analytical solution for the model is obtained through the electromechanical decoupling method. Additionally, experimental investigations are conducted to explore the influence of various bluff body cross-sections and wind speeds on the power generation performance of the piezoelectric laminated beam. The research findings highlight that, under individual galloping excitation, a 30° isosceles triangular bluff body cross-section maximizes the power response. However, under hybrid excitation, the D-shaped bluff body cross-section exhibits the lowest output power due to the absence of galloping excitation.