Thermal tuning of Lamb wave band structure in a two-dimensional phononic crystal plate

Abstract

Using supercell-plane-wave-expansion method, we have made a theoretical study of the temperature effects on the band structure of Lamb wave in a two-dimensional phononic crystal plate. The numerical results show that the Lamb wave bandgap is very sensitive to temperature. For the case of Ba0.7Sr0.3TiO3/epoxy phononic crystal, the width of bandgap becomes narrower in a hexagonal lattice system as the temperature increases, but it becomes wider in a phononic crystal plate with square lattice. On the other hand, for the case of air/Ba0.7Sr0.3TiO3 plate with square lattice, wider and higher complete bandgap can be created in a higher temperature. These results are quite different from that in the infinite phononic crystal and one-dimensional phononic crystal plate.

Thermally tunable band gaps in architected metamaterial structures

“…One way to address this engineering challenge is to develop a structure whose properties adapt to external conditions such as deformation, applied load, applied temperature, and/or humidity. This concept of tunable metamaterials or phononic crystals has been explored in recent literature using deformations [7][8][9], applied loads [10], temperature-sensitive materials [11][12][13][14][15], topological transformation of structures [16][17][18], applied voltage to control the thickness and tension in elastomers [19,20], magneto-granular materials [21] and magnetoelastic mate-rials [22,23]. While prior work has shown the ability to open, close, and generally tune band gaps with a variety of mechanisms, we instead focus on a method to tune the band gaps in a specified direction by analyzing the mode shapes of the meta-structure, given the ability to tune the modulus of the meta-structure constituents with an applied temperature.…”

Asymmetric Lamb Wave Propagation and Mode Isolation in Thin Plate With Spatiotemporal Periodic Stiffness

“…To circumvent these difficulties, filters and wave guides had previously been developed to isolate specific modes of the Lamb wave [6,7], as well as to confine the wave propagation to specific directions [8]. The strategies for mode isolation revolve mainly around the use of phononic crystals, which prevents the transmission of selective wave frequencies through the action of Bragg scattering [9][10][11][12][13][14][15][16][17][18][19][20][21]. To achieve unidirectional transmission, on the other hand, requires breaking either the spatial inversion symmetry or the time-reversal symmetry [22].…”

Phononic Crystal Tunable via Ferroelectric Phase Transition

“…Tuning and switching the hypersonic phononic properties is realized through phase transitions of crystallization and melting, which can be tuned by temperature [15]. Recently, it was suggested that ferroelectric ceramics are suitable for tunable PC, since their acoustic velocities are sensitive to the temperature across Curie temperature (T C ) [18][19][20][21]. Nevertheless, most of these studies were theoretical in nature, and focused on the obvious effects of external stimuli on the band structure of an infinite PC.…”