Two Bimorph Piezoelectric Energy Harvester for Vibrations.
Aryanpur, Rameen.
2017-04-18T13:53:10.814Z
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Abstract: This thesis explores the effectiveness of a two bimorph piezoelectric energy harvester for vibrations. Work in piezoelectric vibration energy harvesting has typically focused on single member cantilevered structures with transverse tip displacement at a known frequency, taking advantage of the optimal coupling characteristics of piezoceramics in the 3-1 bending mode. Many environmental v... read moreibrations, however, are random or wideband, rendering most cantilever energy harvesters sub-optimal. The purpose of the two bimorph energy harvester was to widen the bandwidth of the power frequency response in comparison to cantilever devices as well as to amplify it. Also, the device was designed to prevent significant attenuation of the power response for non-transverse vibration sources. The two bimorph device consisted of two hinged piezoceramic (PZT-5A) beams poled for series operation. Each beam measured 31.8mm x 12.7mm x 0.38mm and consisted of two layers of nickel-plated piezoceramic adhered to a brass center shim. The hinge device consisted of two custom-machined aluminum attachments epoxied to the end of a beam and connected using a 1.59mm diameter alloy steel dowel and torsion spring. Three different configurations of the energy harvester were tested and their power frequency response obtained. It was determined that the two bimorph device generated considerably larger power than the cantilever across a wide low frequency range. This was a marked achievement in that many devices in the literature do not perform well across wide bands at low frequencies where most broadband environmental vibrations are observed. In addition, the two bimorph device prevented significant attenuation of the power response for base excitation not transverse to the structure, but did not introduce additional resonant peaks.
Thesis (M.S.)--Tufts University, 2012.
Submitted to the Dept. of Mechanical Engineering.
Advisor: Robert White.
Committee: Robert Greif, and Luis Dorfmann.
Keyword: Mechanical engineering.read less - ID:
- 2801pt48b
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