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Indexed by:Journal Papers

Date of Publication:2020-02-01

Journal:SENSORS AND ACTUATORS A-PHYSICAL

Included Journals:EI、SCIE

Volume:302

ISSN No.:0924-4247

Key Words:Energy harvester; Piezoelectric; Cruciform beam; Pre-compression; Bandwidth

Abstract:This paper presents a novel pre-compressed cruciform energy harvester (PCEH) with low resonant frequency, wide usable bandwidth, and large voltage peak. The doubly-symmetrical PCEH consists of a pre-compressed main beam with piezoelectric patches and two side beams with concentrated masses attached to free ends. The geometry of the introduced side beams and the pre-compressive force can effectively adjust the overall equivalent mass and stiffness of the proposed PCEH, which in turn affect key properties such as resonant frequency, voltage peak and usable bandwidth. Based on the Euler Bernoulli beam theory and the electromechanically coupled theory, a mechanical model of the novel PCEH is proposed and developed to capture the effects of the side beam geometry and the pre-compressive force on key properties, and subsequently validated by finite element analysis (FEA) and experiments. A comparison between the PCEH and the commonly used pre-compressed energy harvester (PEH) with equal total mass reveals that the newly introduced side beams improve the performances of the PCEH. For example, when a 135N pre-compressive force is applied to both PEH and PCEH, the resonant frequency of the present PCEH is 43.52 % lower than that of the reference PEH by tuning the length of the side beam, and the voltage peak and usable bandwidth of the present PCEH are 149.35 % higher and 35.84 % wider than those of the reference PEH, respectively. A good agreement among the theoretical, FEA and experimental results of the present PCEH is fully verified. (C) 2019 Elsevier B.V. All rights reserved.