Power Generation from Bridge Vibration under Ordinary Vehicle Load

This study conducted the structural eigenvalue analysis on a highway bridge model to investigate its vibration characteristics and to find out an appropriate location to set a new power-generating device using a magnetostrictive element (Fe-Ga alloy). The energy generator is consisting of a Fe-Ga element of 4 x 0.5 x 1.6 mm attached to a U-shaped frame with a permanent magnet for magnetic bias wound about by a coil and the weight attached to the tip of the U-shaped frame was adjusted to allow the frame vibrates with the frequency of the vibration source. First, a part of the elevated line of a highway bridge located in Kanazawa city was reproduced by using a commercial finite element software named DIANA. As the results, at the lateral brace between G1 – G2 main girders and P2 – P3 pier, which its frequency was estimated to be ~ 19Hz, is the optimal place for the device. Moreover, an open-circuit voltage of ~ 8V was recorded. 