Non-linear energy harvesting from coupled impacting beams

Abstract

Energy harvesting has many potential applications for structures with broadband excitation, such as aircraft noise and low frequency vibrations from human motion. The advantage with a vibro-impacting system is the capability of converting low frequency response to high frequencies. A coupled beam system is base excited and the influence of different system parameters are studied. Exciting the system at a single resonant frequency highlights the influence of clearance and base excitation amplitude on the beam responses. The frequency sweep study shows the sensitivity of the power generated to the contact stiffness, damping and clearance between the beams. The power generated by the coupled system from the non-linear impact is sensitive to the thickness ratio of the beams and the clearance. The variation in thickness ratio alters the spacing of the natural frequencies of the system which causes modes to interact. This study shows that higher power is produced than the linear system, depending on the dissimilarity in the mode shapes of the interacting close modes.