Inerter-enhanced piezoelectric energy harvesting for vehicle-induced bridge vibrations: Analytical modeling and optimal parameter design

A novel inerter-based piezoelectric energy harvester is designed for low-frequency vibration applications. The incorporation of the inerter enhances system coupling, enabling the device to reach peak output power more readily. Two SDOF configurations are presented and analyzed through a unified electromechanical model. To validate this approach, numerical simulations were conducted using harmonic and white noise excitations, followed by tests using simulated bridge stochastic excitations as input. The proposed devices achieve several fold enhancement in output power under specific operating conditions. Key findings demonstrate that incorporating the inerter significantly reduces the strong coupling threshold by approximately 45%, while enabling equal power output at two distinct resonant frequencies when exceeding the critical coupling strength. Under harmonic excitation, both configurations achieve more than 44% reduction in resonant frequency. The series configuration (IS-PEH) exhibits quadratic power growth with increasing inerter mass ratio, delivering 902% enhancement under harmonic excitation and significant efficiency improvement under random vibration. The device demonstrates significant potential for low-frequency energy harvesting, showing promise in advancing the development of low-frequency energy harvesting technology for structural monitoring applications.