Failure analysis for vibration-based energy harvester utilized in high-speed railroad vehicle

This study aims to analyze the failure mechanism and improve the structural design of a vibration-based energy harvester (VEH), which intends to replace or extend the service life of batteries for condition monitoring systems of high-risk structures such as railroad vehicles and wind turbines. The observation of a fractured VEH under service condition of high-speed railway vehicle reveals several cracks originating on the surface of the VEH. A vibration test in the laboratory, conducted by using an electromagnetic exciter, identifies the resonant frequency, displacement-frequency, and acceleration-frequency plots of the VEH. A comparison of the surface fractured during vibration testing with that under service condition indicates that the major failure mechanism is static brittle fracture. The failure critical location and stress states are identified through frequency response analysis. Several measures are recommended to prevent the failure of VEHs, including selecting materials and redesigning the moving component of VEH.