Response regime of nonlinear bistable energy harvester

The effective bandwidth of a bi-stable electromechanical energy harvester is investigated. The Harvester’s configuration is in the form of a cantilever beam in which the piezoelectric layers are attached on its two sides. The whole device undergoes sinusoidal base excitation. In addition an axial force is applied to the end of the beam. Post-buckling is caused by this force and system becomes bistable. The cantilever beam is modeled as a nonlinear Euler-Bernoulli beam and equations of motion are generated using Lagrangian method. The equations then discretize via Assumed Mode method and governing equations are solved via Complexification Averaging solution and compared with numerical results. Different attractors such as periodic, quasi-periodic and chaotic attractors are detected and their relative frequency domains are identified. Using semi-solution method, boundaries of different areas plotted in the base excitation-frequency domain. Finally, Uni-modal and multimodal cases are studied and compared with each other. It is shown that the uni-modal solution does not predict the behavior of the system correctly.