Research on the Performance Laws of the Piezoelectric Beam and Magnetic Coupling Module of the Magnetic-Coupled Double-Wing Negative Stiffness Energy Harvester

With the rapid development of urban rail transit, the floating slab vibration isolation system has become widely used in the field due to its effective vibration reduction and isolation capabilities. Traditional floating slab vibration-isolation systems mainly focus on blocking vibration transmission, neglecting energy harvesting. This paper proposes a magnetic-coupled double-wing negative stiffness energy harvester for floating slabs. A single-wing piezoelectric beam model and a finite element model of the magnetic-coupled module are established. The modal and output characteristics of the single-wing piezoelectric beam are analyzed. Furthermore, the force characteristics of the magnetically coupled negative stiffness module are analyzed. The results show that the contribution of its width to the modal frequency gradually decreases with an increase in the length of the single-wing piezoelectric beam. The thickness significantly influences the characteristic frequency, and the load is exponentially related to the output power. At the optimal load and characteristic frequency of the single-wing piezoelectric beam, the output characteristics decrease with an increase in the width. The peak value of the magnetic-coupled negative stiffness gradually decreases with an increase in the magnetic gap. The increase in remanent magnetic strength indicates that the initial state of the magnetic ring is more easily affected by external conditions. The change in axial magnetic force becomes significant with increased displacement. This research enriches the theoretical systems of piezoelectric energy harvesting technology and magnetic-coupled negative stiffness mechanism while providing important theoretical support for subsequent experimental research, optimal design, and practical applications.