Segmentation of a Vibro-Shock Cantilever-Type Piezoelectric Energy Harvester Operating in Higher Transverse Vibration Modes

Sensors

Darius Zizys¹  Rimvydas Gaidys¹  Rolanas Dauksevicius³  Vytautas Ostasevicius³  Vytautas Daniulaitis² 

[1] Faculty of Mechanical Engineering and Design, Kaunas University of Technology, Studentu 56, Kaunas LT-51368, Lithuania;Faculty of Informatics, Kaunas University of Technology, Studentu 50, Kaunas LT-51368, Lithuania;Institute of Mechatronics, Kaunas University of Technology, Studentu 56-123, Kaunas LT-51368, Lithuania;

关键词: piezoelectric;    optimal segmentation;    vibration energy harvesting;    resonant frequency;    strain node;    numerical modelling;   

DOI  :  10.3390/s16010011

来源: mdpi

【 摘 要 】

The piezoelectric transduction mechanism is a common vibration-to-electric energy harvesting approach. Piezoelectric energy harvesters are typically mounted on a vibrating host structure, whereby alternating voltage output is generated by a dynamic strain field. A design target in this case is to match the natural frequency of the harvester to the ambient excitation frequency for the device to operate in resonance mode, thus significantly increasing vibration amplitudes and, as a result, energy output. Other fundamental vibration modes have strain nodes, where the dynamic strain field changes sign in the direction of the cantilever length. The paper reports on a dimensionless numerical transient analysis of a cantilever of a constant cross-section and an optimally-shaped cantilever with the objective to accurately predict the position of a strain node. Total effective strain produced by both cantilevers segmented at the strain node is calculated via transient analysis and compared to the strain output produced by the cantilevers segmented at strain nodes obtained from modal analysis, demonstrating a 7% increase in energy output. Theoretical results were experimentally verified by using open-circuit voltage values measured for the cantilevers segmented at optimal and suboptimal segmentation lines.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.