One of the most daunting limitations of phononic crystals and acoustic/elastic metamaterials is their passivity: a given configuration is bound to display its phononic properties only around its design point, i.e., working at some pre-determined operating conditions. In the past decade, this shortcoming has inspired the design of phononic media with tunable wave characteristics; noteworthy results have been obtained through a family of methodologies involving shunted piezoelectric elements. Shunting a piezoelectric element means connecting it to a passive electric circuit; tunability stems from the ability to modify the effective mechanical properties of the piezoelectric medium by modifying the circuit characteristics. One of the most popular shunting circuits is the resistor-inductor, which allows the patch-and-shunt system to behave as an electromechanical resonator. A common motif among the works employing shunted piezos for phononic control is periodicity: the patches are typically periodically placed in the domain and the circuits are identically tuned. The objective of this work is to demonstrate that the wave attenuation performance of structures with shunted piezoelectric patches can be improved by leveraging notions of organized disorder. Based on the idea of rainbow trapping broadband wave attenuation obtained by tuning an array of resonators at distinct neighboring frequencies we design and test an electromechanical waveguide structure capable of attenuating waves over broad frequency ranges. In order to emphasize the fact that periodicity is not a binding requirement when working with RL shunts (which induce locally resonant bandgaps), we report on the performance of random arrangements of patches. In an attempt to demonstrate the tunability attribute of our strategy, we take advantage of the reconfigurability of the circuits to show how a single waveguide can attenuate both waves and vibrations over different frequency ranges.
|Original language||English (US)|
|Title of host publication||Health Monitoring of Structural and Biological Systems 2017|
|State||Published - 2017|
|Event||Health Monitoring of Structural and Biological Systems 2017 - Portland, United States|
Duration: Mar 26 2017 → Mar 29 2017
|Name||Proceedings of SPIE - The International Society for Optical Engineering|
|Other||Health Monitoring of Structural and Biological Systems 2017|
|Period||3/26/17 → 3/29/17|
Bibliographical noteFunding Information:
ACKNOWLEDGMENTS This work has been supported by the National Science Foundation (grant CMMI-1266089). P.C. wishes to acknowledge the support of the University of Minnesota through the Doctoral Dissertation Fellowship. W.Z. acknowledges the support of the Internship Opportunities Program from the Department of Civil, Environmental, and Geo-Engineering at the University of Minnesota.
- Shunted piezoelectrics
- Vibration control
- Wave control