A bistable energy harvester for friction-induced stick–slip vibration.

A bistable energy harvester incorporated in a friction system is modelled and numerically investigated, aiming to realize an improved power extraction from stick–slip vibration. Kinetic energy is converted into electricity through piezoelectric patches, and bistability is achieved via two magnets. The theoretical results indicate that large-amplitude periodic motion of the nonlinear energy harvester can be triggered by the stick–slip limit cycle excitations. However, under the influence of the loading force and the belt velocity, the vibration pattern of the energy harvester can be very complicated, which exhibits abundant bifurcation behaviour. Quasi-periodic and chaotic oscillations can happen when the loading force gets large. Small-amplitude intrawell oscillation happens at low sliding velocities, while large-amplitude periodic oscillation occurs when the belt velocity increases to a level at which the stick–slip excitation is strong enough to provide sufficient energy to make the tip magnet escape the potential barrier. In addition, coexistence solutions of periodic and chaotic oscillations can be observed at some sliding velocities due to the nonlinear effects of the energy harvester and the negative gradient of friction versus the relative velocity. To fully understand the vibration behaviour of the energy harvester, a solution map is plotted in terms of loading force and belt velocity according to numerical simulation results. In the end, an experimental work is performed to prove the theoretical investigation. [ABSTRACT FROM AUTHOR]