A Computational Study on the Vibrational Energy Harvesting from Bimorph Beams with Particulate Piezocomposite Layers: Micro-to-Macro Mechanical Simulations
Abstract
Purpose: The engineering design of vibrational energy harvesters consisting of piezocomposites is generally a challenging task because of various parameters involved at micro- and macro-scales. This paper aims to comprehensively evaluate vibration energy harvesting from a clamped-free bimorph beam with two layers of particulate piezocomposites. Methods: In this study, a multi-phase computational approach is employed to address the vibration energy harvesting using clamp-free piezocomposite bimorph beams. Two types of piezocomposites are examined, featuring LaRC-SI polyamide as the matrix and BaTiO₃ and PZT-7A as piezoelectric fillers. Using the micromechanical finite element method, electromechanical properties of the representative volume element (RVE) of the piezocomposites are predicted. The parametric studies are conducted to predict and compare output voltage and power, considering factors such as the volume fraction, geometry and type of piezoelectric filler, the series or parallel configuration of the circuit. The mode shapes and natural frequencies under structural weight are also analyzed. Results and Conclusion: The results reveal that increasing the volume fraction of piezoelectric fillers enhances electromechanical properties, leading to higher voltage and power output. Bimorph beams are shown to extract more electrical outputs compared to unimorph beams of the same piezocomposite characteristics. Additionally, a parallel circuit connection of the piezocomposite layers in a bimorph beam enhances the electrical outputs compared to a series connection. It is found that the output voltage and power are significantly increased as the piezoelectric filler aspect ratio increases. The frequency related to the peak voltage and power increases as the fillers’ geometry deviates more from spherical shape. © Springer Nature Singapore Pte Ltd. 2025.