Snap-through dynamics between the two potential wells of bistable oscillators are exhibited over a wide frequency range which narrows with decreasing harmonic excitation amplitudes until disappearing at a critical forcing level. However, for efficient conversion from vibrational to electrical energy in harvesting applications, the bistable oscillator must retain its favorable broadband cross-well response while the input excitation is minimized. To maintain effectiveness at low forcing levels, an actuation approach is proposed where external perturbations are used to extend the oscillator’s cross-well bandwidths by switching from co-existing low to high energy attractors. By utilizing Macro Fiber Composites (MFC) in a [0^MFC /90^MFC ]_T bistable laminate, the application of rectangular voltage pulse signals are cycled through different response phases to continuously alter the basins of attraction until the desired cross-well orbit is sustained at each frequency. The pulse magnitude is where the system exhibits limit point behavior and the resulting snap through actuation mechanism brings consistency between perturbation trials. Numerical simulations show significant increase to the bandwidths inducing cross-well oscillations when the perturbation strategy is employed.

Date Published: 21 March 2019
PDF: 12 pages
Proc. SPIE 10967, Active and Passive Smart Structures and Integrated Systems XIII, 109670H (21 March 2019); doi: 10.1117/12.2514104

Published in SPIE Proceedings Vol. 10967:
Active and Passive Smart Structures and Integrated Systems XIII
Alper Erturk, Editor(s)