Finite element-based assessment of energy harvesting in composite beams with piezoelectric transducers

A finite element-based methodology is introduced for studying composite beams with piezoelectric transducers connected to energy harvesting circuits. Continuous and lumped-parameter models are developed based on finite element approximations and verified by means of experiments performed on a cantilever beam subjected to sinusoidal excitation at low, with respect to resonance, frequencies below 15 Hz. Three harvesting circuits have been studied: an in-house, a commercial, modified to include a rectification stage, and an off-the-shelf commercial. Comparison of numerical predictions with experiments illustrates good agreement in voltage and high sensitivity to current losses in the circuit. It was found that the commercial circuits outperform the in-house circuit in terms of harvested power at frequencies higher than 5 Hz, while the latter enables power harvesting at arbitrary low frequencies. Based on these results, it is demonstrated that the developed approach enables coupled simulation of a composite structure and a realistic harvesting circuit in one-shot. © IMechE 2021