Stubbed plates, i.e., thin elastic sheets endowed with pillar-like resonators, display subwavelength, locally resonant bandgaps that are primarily controlled by the intrinsic resonance properties of the pillars. In this work, we experimentally study the bandgap response of a tunable heterogeneous plate endowed with reconfigurable families of pillars. We demonstrate that, under certain circumstances, both the spectrum of resonant frequencies of the pillars and their spatial arrangement influence the filtering characteristics of the system. Specifically, both spatially graded and disordered arrangements result in bandgap widening. Moreover, the spectral range over which attenuation is achieved with random arrangements is on average wider than the one observed with graded configurations.
Bibliographical noteFunding Information:
S.G. and P.C. acknowledge support from the National Science Foundation (CMMI-1266089). P.C. acknowledges support from the University of Minnesota Doctoral Dissertation Fellowship. B.Y. acknowledges support from the Natural Science and Engineering Research Council of Canada through a postdoctoral fellowship. C.D. and B.Y. acknowledge partial support from the National Science Foundation (EFRI-1741565). We thank W. Zhang, N. Bausman, M. Turos, A. Palermo, V. Tournat, and A. Cebrecos for their help and fruitful discussions.