TY - JOUR
T1 - Relative performance of a vibratory energy harvester in mono- and bi-stable potentials
AU - Masana, Ravindra
AU - Daqaq, Mohammed F.
N1 - Funding Information:
The authors would like to acknowledge the generous support of the National Science Foundation (NSF) through NSF CAREER grant CMMI-1055419 “CAREER: Electromechanical Transduction of Vibratory Energy Harvesters in Random and Non-Stationary Environments”. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/11/21
Y1 - 2011/11/21
N2 - Motivated by the need for broadband vibratory energy harvesting, many research studies have recently proposed energy harvesters with nonlinear characteristics. Based on the shape of their potential function, such devices are classified as either mono- or bi-stable energy harvesters. This paper aims to investigate the relative performance of these two classes under similar excitations and electric loading conditions. To achieve this goal, an energy harvester consisting of a clampedclamped piezoelectric beam bi-morph is considered. The shape of the harvesters potential function is altered by applying a static compressive axial load at one end of the beam. This permits operation in the mono-stable (pre-buckling) and bi-stable (post-buckling) configurations. For the purpose of performance comparison, the axial load is used to tune the harvesters oscillation frequencies around the static equilibria such that they have equal values in the mono- and bi-stable configurations. The harvester is subjected to harmonic base excitations of different magnitudes and a slowly varying frequency spanning a wide band around the tuned oscillation frequency. The output voltage measured across a purely resistive load is compared over the frequency range considered. Two cases are discussed; the first compares the performance when the bi-stable harvester has deep potential wells, while the second treats a bi-stable harvester with shallow wells. Both numerical and experimental results demonstrate the essential role that the potential shape plays in conjunction with the base acceleration to determine whether the bi-stable harvester can outperform the mono-stable one and for what range of frequencies. Results also illustrate that, for a bi-stable harvester with shallow potential wells, super-harmonic resonances can activate the inter-well dynamics even for a small base acceleration, thereby producing large voltages in the low frequency range.
AB - Motivated by the need for broadband vibratory energy harvesting, many research studies have recently proposed energy harvesters with nonlinear characteristics. Based on the shape of their potential function, such devices are classified as either mono- or bi-stable energy harvesters. This paper aims to investigate the relative performance of these two classes under similar excitations and electric loading conditions. To achieve this goal, an energy harvester consisting of a clampedclamped piezoelectric beam bi-morph is considered. The shape of the harvesters potential function is altered by applying a static compressive axial load at one end of the beam. This permits operation in the mono-stable (pre-buckling) and bi-stable (post-buckling) configurations. For the purpose of performance comparison, the axial load is used to tune the harvesters oscillation frequencies around the static equilibria such that they have equal values in the mono- and bi-stable configurations. The harvester is subjected to harmonic base excitations of different magnitudes and a slowly varying frequency spanning a wide band around the tuned oscillation frequency. The output voltage measured across a purely resistive load is compared over the frequency range considered. Two cases are discussed; the first compares the performance when the bi-stable harvester has deep potential wells, while the second treats a bi-stable harvester with shallow wells. Both numerical and experimental results demonstrate the essential role that the potential shape plays in conjunction with the base acceleration to determine whether the bi-stable harvester can outperform the mono-stable one and for what range of frequencies. Results also illustrate that, for a bi-stable harvester with shallow potential wells, super-harmonic resonances can activate the inter-well dynamics even for a small base acceleration, thereby producing large voltages in the low frequency range.
UR - http://www.scopus.com/inward/record.url?scp=80052263010&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80052263010&partnerID=8YFLogxK
U2 - 10.1016/j.jsv.2011.07.031
DO - 10.1016/j.jsv.2011.07.031
M3 - Article
AN - SCOPUS:80052263010
SN - 0022-460X
VL - 330
SP - 6036
EP - 6052
JO - Journal of Sound and Vibration
JF - Journal of Sound and Vibration
IS - 24
ER -