Periodic solutions and bifurcations of a tristable flutter-based energy harvester

This paper designs a tristable flutter-based energy harvester that can harvest large amplitude interwell wind-induced vibration energy. To explore its periodic responses and bifurcation characteristics, the harmonic balance method and the incremental harmonic balance method are employed to solve its approximate solutions by combining the two-point tracing algorithm. By analyzing the incremental harmonic balance solutions, three different response regions and five vibration types are found. The wind tunnel experiment verifies the existence of these vibration types and the correctness of incremental harmonic balance solutions. Five bifurcation points are analyzed using the Floquet theory, and two evolution paths of its periodic solutions are studied. Finally, the influences of the potential well depths on the stable periodic solutions are studied. The shallow potential energy well is beneficial to improving the response stability. This study aims to fill the gap in the semi-analytical and analytical solution of nonlinear flutter-based energy harvesters, contribute to the theoretical analysis of wind-induced vibration energy harvesting, and provide more possibilities for the design of high-performance wind-induced vibration energy harvesters.