Acoustic wave transmission in time-varying phononic crystals

作者：Wright D W^*; Cobbold R S C

来源：Smart Materials and Structures, 2009, 18(1): 015008.

DOI：10.1088/0964-1726/18/1/015008

Phononic crystal effects are typically narrowband and highly dependent on the size and spacing of the scatterers within the crystal-properties that are fixed and unchangeable. We propose that it may be possible to dynamically alter the behaviour of phononic crystals by varying the material properties in time. In this paper we seek to extend the existing static phononic crystal theory so as to handle time-varying material parameters and also to provide insight into the factors that govern their behaviour. Beginning with the transmission matrix method, we develop a new method to determine the acoustic wave transmission through a time-varying corrugated tube waveguide, which is analogous to a one-dimensional (1D) phononic crystal. These expressions are further developed for periodic material parameter variation signals. Our method permits the development of a closed-form solution to the acoustic wave transmission through a 1D time-varying phononic crystal. It shows excellent agreement with finite-difference time- domain simulations and with execution times several orders of magnitude faster. Preliminary results show that the band-gap properties can be significantly altered using material parameter time variation as the driving mechanism.

• 出版日期2009-1