Modeling and optimization of acantilevered energy harvester partially covered by a macro fiber vomposite patch

Piezoelectric energy harvesters (PEH) are recognized as smart structural devices, offering researchers an innovative approach to estimate the energy harvested from real vibration sources. This work presents linear analytical methods for predicting the energy harvested from an unimorph cantilevered beam with a proof mass, with a substrate partially covered by a Macro Fiber Composite (MFC) patch. In order to enhance a PEH that can generate more density of electrical power, a new framework for MFC harvesters with discontinuous geometries using Euler-Bernoulli assumptions is proposed. The length of the harvester can be divided into three parts of uniform beams followed by applying appropriate continuity conditions. Mixing rules are used to derive the equivalent properties of the MFC patch which is considered as five layers. The active layer contains a piezoceramic macro fibers embedded within an epoxy matrix, which is fully covered by electrode and Kapton layers. The excitation of the system is assumed to be at its base. The proposed method is validated through experimental comparison issued from the literature. The results indicate that the location of the MFC patch has a significantly affect to the density of electrical power, the optimal resistance and the natural frequencies.