Experimental study of dynamic vibration absorber and energy harvester

In this study, application of a dynamic vibration absorber system consists of two symmetric cantilever beams with tip mass and piezoelectric layer, in order to suppress undesired vibrations and harvest electrical energy, is studied. The main vibratory system is a simply supported beam, which is excited by a DC motor with rotating unbalance mass. To derive the governing electromechanical equations, the Euler-Bernoulli beam theory and the energy method are used. Then the governing electromechanical equations are experimentally validated and accommodation between theoretical and experimental results is shown using several frequency response plots. Using the non-dimensional governing equations, effect of changing the system parameters such as the tip mass, load resistance and length of the cantilever beam is studied. Then, considering ability of system to effectively suppress undesired vibrations and increase the harvested electrical energy, the proper range for selecting the non-dimensional tip mass and non-dimensional load resistance is presented. Finally, using the so-called perfection rate parameter, the best parameters, to have a good vibration suppressor and energy harvester, are obtained. Results shown that both of energy and vibration considerations can be satisfied using the system.