Harvest more bridge vibration energy by nonlinear multi-stable piezomagnetoelastic harvester

The idea of using bridge vibration energy to power node sensors is promising in solving the power problems of bridge health monitoring systems. This study proposes a piezomagnetoelastic harvester that tries utilizing nonlinear multi-stability to improve the harvesting performance of bridge vibration energy. The harvester can exhibit multi-stable behaviors due to the introduced nonlinear forces. The potential energy functions are derived and corresponding analyzes are carried out. The results show that the tri-stable state of harvester can be obtained by adjusting the parameters related to magnetic forces. Its potential barriers are low and the distance between potential wells is large, so it can execute snap-through motion easily. The experimental study was carried out for different vehicle speeds. The results verify that the energy harvester in a tri-stable state can generate the largest electric output over a wide range of vehicle speeds. Moreover, it is proved that the tri-stable state can protect the harvester from excessive deformation and subsequent damage. Therefore, the tri-stable configuration has a potential advantage in bridge vibration energy harvesting and providing power for self-powered sensors.