Experimental Validation of an Impact Off-resonance Energy Harvester
G Martínez-Ayuso, MI Friswell, H Haddad Khodaparast & S Adhikari (Swansea University)
European Physical Journal - Special Topics, Vol. 228, No. 7, August 2019, pp. 1635-1646
Most piezoelectric energy harvesting research has focused on developing on-resonance harvesters that work at low frequencies, even though higher frequencies can generate more power. In addition, conventional resonant harvesters have low efficiency when the excitation frequency is away from resonance. Using mechanical impacts has the potential to improve the overall harvested energy since high frequencies are excited during impacts. Also, the presence of impacts reduces the influence of the base excitation frequency and the requirement to exactly match the resonance frequency. To take advantage of the higher frequency response, an impact energy harvester is designed and validated experimentally. The harvester consists of a cantilever beam with a piezoelectric patch attached to its base which impacts with a stiff object. The harvester is modelled using finite element analysis and a Hertzian contact law. The model is tested and validated in the laboratory using an in-house manufactured demonstrator. Good agreement with the experimental data is obtained, setting the basis for future optimisation of the harvester geometry and piezoelectric properties.
This material has been published in the European Physical Journal - Special Topics, Vol. 228, No. 7, August 2019, pp. 1635-1646. This paper is open access.
Link to paper using doi: 10.1140/epjst/e2019-800155-0
European Physical Journal - Special Topics