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Energy Harvesting Using a Nonlinear Energy Sink
Date: 2015/5/14             Browse: 542

Speaker: Dr. Kefu Liu

Time: May.14, 3:15-4:30pm

Location: Room 220, Building 8

Abstract:

A linear vibration absorber is very effective to suppress vibration 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. How to achieve both 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 possesses a broad band of energy localization and dissipation. In this talk we introduce an energy harvester that is based on the NES principle. First we briefly explain the principle of the NES. Then we present the proposed design and its dynamic model. We investigate the system parameter identification and the energy transduction relationship. Finally we test the performance of the device experimentally. Using the results, we show that the device is capable of suppressing vibration and harvesting energy in a broad band manner.

Bio:

Dr. Kefu Liu received his B.Eng. degree and M.Sc. degree in Mechanical Engineering from Central South University in China in 1981 and 1984, respectively. He obtained his Ph.D. degree in Mechanical Engineering from Technical University of Nova Scotia in Canada in 1992. From 1993 to 1995, he was Assistant Professor at St. Mary's University. From 1995 to 1998, he was Assistant Professor at Dalhousie University. He joined Lakehead University as Assistant Professor in the Department of Mechanical Engineering in 1998. He became Associate Professor in 2001 and Full Professor in 2005. Dr. Liu is a member of the Canadian Society of Mechanical Engineering (CSME), and Professional Engineers Ontario (PEO). Dr. Liu’s research interests cover the following areas: vibration theory, vibration control, energy harvesting using ambient vibration, control of nonlinear systems, identification of time-varying systems, machine condition monitoring and diagnosis, parallel mechanical manipulators, mechatronics. He has published more than 50 international journal papers and 30 international conference papers. He has trained 10 M.Sc. graduate students, two Ph.D. students (co-supervision), and 3 Postdoctoral fellows (co-supervision). Dr. Liu is a holder of Discovery grant of the Natural Sciences and Engineering Research Council of Canada. He is a regular reviewer for several international journals and conferences. He is a reviewer for several funding organizations including NSERC Canada, ISTP Canada, RGC Hong Kong.                                                      

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