Energy harvesting in a nonlinear cantilever beam system excited by harmonic and random vibrations

Abstract

The nonlinear beam with vertical combined excitations is proposed as an energy harvester. The system is modelled as a cantilever beam with included a tip mass and piezoelectric patches which transduce the bending strains induced by both, the harmonic and as an additive stochastic forces. The excitation affects in vertical directions by kinematic forcing into electrical charge. The main goal is to analyse the dynamics of the electro-mechanical beam system and the influence of the mixed excitation forces into an effectiveness of the energy harvesting. Overcoming the potential barrier by the beam system is also analysed, where large output amplitudes occur. Such region of the vibration affects more power generation as well as voltage spikes, which is crucial in terms of load resistors sensitivities. By increasing the additive noise level with fixed harmonic force we observe the transition from single well oscillations to inter-well stochastic jumps, and the output power is measured during different system behaviours.