Energy Harvesting Using a Nonlinear Energy Sink
Prof Kefu Liu
Lakehead University, Canada
Time & Place
Thu, 26 May 2016 12:20:00 NZST in HP Seminar Room, John Britten Bldg
A linear vibration absorber is an effective device for vibration suppression of a primary system subjected to a harmonic excitation. However, its performance is sensitive to variation of operational conditions such as the exciting frequency. On the other hand, a linear energy harvester must be tuned to resonate with ambient vibration. Therefore, its efficiency is limited to a small region of frequencies. Simultaneous vibration suppression and energy harvesting in a broad band manner is of significance in applications.
A nonlinear energy sink (NES) consists of a mass, a spring with an essential nonlinearity, and a damper. Due to lack of a linear stiffness, the NES can respond to any frequency as long as the excitation level reaches a certain threshold. In this sense, the NES is capable of broad band energy localization and dissipation. This talk introduces a variant NES energy harvester developed at Lakehead University. First the principle of the NES is briefly explained. Then the proposed design is presented and its dynamic model is developed. The system parameter identification and the energy transduction relationship are discussed. Finally the transient performance of the device is examined experimentally. The study shows that the device is capable of suppressing vibration and harvesting energy in a broad band manner.