Robust energy harvesting from walking vibrations by means of nonlinear cantilever beams

• Published in: Journal of sound and vibration Vol. 341; pp. 174 - 194
• Main Authors: Kluger, Jocelyn M, Sapsis, Themistoklis P, Slocum, Alexander H
• Format: Journal Article
• Language: English
• Published: 04.04.2015
• Subjects: Damping; Dynamical systems; Energy harvesting; Excitation; Nonlinearity; Optimization; Robustness; Vibration
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2014.12.035

In the present work we examine how mechanical nonlinearity can be appropriately utilized to achieve strong robustness of performance in an energy harvesting setting. More specifically, for energy harvesting applications, a great challenge is the uncertain character of the excitation. The combination of this uncertainty with the narrow range of good performance for linear oscillators creates the need for more robust designs that adapt to a wider range of excitation signals. The studied nonlinear mechanism has favorable mechanical properties such as low frictional losses, minimal moving parts, and a rugged design that can withstand excessive loads. The optimization results show that the 2DOF nonlinear system presents the best average performance when the excitation signals have three possible forms. Moreover, we observe that while for the linear systems the optimal performance is obtained for small values of the electromagnetic damping, for the 2DOF nonlinear system optimal performance is achieved for large values of damping. This feature is of particular importance for the system's robustness to parasitic damping.