Grigoris C. Kardarakosa, Nikolaos A. Chrysochoidisa, Dimitris Varelisc, Dimitris A. Saravanosa, Theofanis S. Plagianakosb, Panagiotis Vartholomeosb, Nikolaos Leventakisb, G. Bolanakisb, Nikolaos Margelisb, Evangelos G. Papadopoulosb
aStructural Analysis and Adaptive Materials Group, Dept. of Mechanical and Aeronautical Engineering, University of Patras, 26500 Patras, Greece; bControl Systems Lab, School of Mechanical Engineering, National Technical University of Athens, 15780 Athens, Greece, cDepartment of Aeronautical Sciences, Hellenic Air Force Academy, 13672 Athens, Greece
Energy harvesting from oscillating structures receives a lot of research attention as these applications appear promising for the continuous energy supply of low power devices. Recent studies indicate increased power production of piezoelectric energy harvester configurations undergoing severe nonlinear vibrations, but the obvious drawback is the increased complexity of the coupled electromechanical dynamic response of the harvester. The current study focuses on the development of a robust and accurate numerical tool capable of modelling and design of such systems. This model is used to simulate the electromechanical response of composite strip structures equipped with piezoelectric devices subjected to nonlinear oscillations under compressive loading and near buckling instability conditions. The study is combined with experimental verification studies on a fabricated harvester prototype aiming to validate the numerical tool and to corroborate the electrical voltage generation on the piezoelectric devices. Additionally, a preliminary experimental study is performed to quantify the available electrical energy that is produced from the oscillating structure. Three different harvesting circuits are studied and their energy conversion performance is investigated. Measured results validate the developed numerical tool. Moreover, the increased electrical voltage and charge generation during the geometrically nonlinear oscillations as the prebuckling load increases, increasing also the available electrical power on the circuits, is illustrated numerically and experimentally.