Energy Harvesting from Train Vibrations

An investigation is carried out into how much energy can be harvested from the vibration of a passing train using a mechanical oscillator. The harvested energy could be used, for example, to charge sensors mounted on the railway track for structural health monitoring. The dominant frequencies due to a passing train are determined for a specific train and speed from a recorded acceleration time-history. Using a simple model of an oscillator, the total energy harvested during the passage of one train is calculated. The stiffness, and hence the tuning frequency of the device, is varied in simulations to determine the optimum frequency at which to tune the device for a constant value of mass and damping in the device. Further simulations are conducted to investigate the power that could be harvested from multiple oscillators tuned at several dominant frequencies, and their performances are analysed and compared. The constraint for maximum relative displacement is considered for each harvester, which is adopted to ensure that the amplitude of the oscillation does not exceed the physical size of the device.