Influence of Potential Well Depth on the Dual−Coupling Beam Energy Harvester: Modeling and Experimental Validation

This paper presents an investigation into the influence of varying potential well depths on the performance of a dual−coupled beam energy harvester (DEH). Firstly, three varying potential well depths were established with different polynomial coefficients of nonlinear restoring force and analyzed in simulation. Numerical results revealed that whether the initial potential well depth is shallow or not, the optimal power output can be attained when the stiffness of the coupling spring is a half of the monostable−to−bistable coupling spring stiffness, which was also validated by an experiment. Specifically, at a deeper initial potential well depth of 0.64 mJ, the system demonstrated superior energy conversion capabilities. Compared to traditional BEH and LEH, the output RMS voltage of Beam 1 and total RMS power of the DEH increased by 103.06% and 49.6%, respectively. The RMS power increased by 16.4% at a potential well depth of 0.9 mJ. In addition, regardless of the potential well depth, the DEH can always achieve the optimal operating bandwidth when the coupling spring stiffness is near the monostable−to−bistable transition region.