Experimental Investigation on Band Gaps Stability for Two-Dimensional Phononic Crystal with Square-Like Archimedean Lattice

The band gaps of phononic crystal(PC) composed of(32.4.3.4) lattice array of circular steel cylinders in water have been investigated both theoretically and experimentally with the plane wave expansion method and the ultrasonic immersion transmission technique.Compared with the PC consisting of square array of circular steel cylinders in water at the same radius and distance between the adjacent steels cylinders,the(32.4.3.4) lattice PC may open the two band gaps in the range of higher frequency.The transmission spectra of different layers of(32.4.3.4) lattice PC were measured experimentally along the Γ-X and Γ-M directions of first irreducible Brillouin zone.The relations of band gaps stability and layers can be discussed in detail.This is better advantage of design for the finite-sized isolating noise materials.A good agreement between the frequency range of transmission spectra of acoustic waves for this crystal and theoretical predict with plane wave expansion method is observed.