Band Gaps of Lamb Waves Propagating in One-Dimensional Different Quasi-Periodic Composite Thin Plates

Abstract

We present a comparative study on band-gap structures of Lamb waves propagating in one-dimensional quasi-periodic composite thin plates, which are composed of different quasi-periodic models such as Cantor, Fibonacci, Thue-Morse, and Double periodic sequences, respectively. The transmitted power spectra (TPS) of the transient Lamb waves propagating in composite plates is calculated numerically by employing the finite element method. By comparing among TPS in different plates with the different ratios of the plate thickness to the lattice spacing, it is found that different quasi-periodic models present different behavior of the split-up of band gaps. Our works are significant not only for understanding intrinsic physical property of the quasi-periodic sequences, but also for designing the special structures of quasi-periodic arrays to adjust the width of band gaps and the frequency ranges of phononic crystals in applications.