Reconfigurable coupled-resonator acoustoelastic waveguides in fluid-filled phononic metaplates

We study numerically and experimentally acoustoelastic wave propagation in a two-dimensional phononic metaplate consisting of a periodic array of cups sitting on a thin epoxy plate that is perforated with cross holes. When all cups are filled with water, the metaplate possesses a complete band gap. Reconfigurable coupled-resonator acoustoelastic waveguides (CRAEWs) are created by locally emptying certain cups, thus introducing local resonances that are evanescently coupled. Straight and 90 degrees bent periodic waveguides are considered, together with an aperiodic chain of 11 coupled resonators. The aperiodic chain has no definite spatial periodicity but supports collective resonances resulting from the coupling of nearest resonators. Lamb waves are experimentally excited by a piezoelectric patch and received by a scanning optical vibrometer. Experimental results for acoustoelastic wave propagation along both periodic and aperiodic CRAEWs are compared to a three-dimensional finite element model taking fluid-structure interaction into account. The propagation of confined acoustoelastic waves in the 90 degrees bent waveguides and the collective resonances of the aperiodic chain of defected resonators are observed experimentally. Reconfigurability are realized based on the coupling of acoustoelastic waves in a phononic metaplate. Our results show plenty of potential possibilities for the practical design of reconfigurable and programmable elastic wave devices.

Automated summary

In this study, we investigated the propagation of acoustoelastic waves in a two-dimensional phononic metaplate through numerical simulations and experiments. By selectively emptying certain cups, reconfigurable coupled-resonator acoustoelastic waveguides were created, and the 90 degrees bent waveguides and the collective resonances of the aperiodic chain were observed. The experimental results were compared to a three-dimensional finite element model, taking fluid-structure interaction into account. This study demonstrates the potential for designing reconfigurable and programmable elastic wave devices.