Band Gaps of 2D Phononic Crystal with Imperfect Interface

Propagation characteristics of elastic waves in 2D phononic crystal consisting of parallel cylinders embedded periodically in a homogeneous host medium are investigated. The multiple scattering method and the Bloch wave theory in a periodic system are used to derive the dispersive equation. Dispersive curves are evaluated numerically in the reduced Brillouin zone and the wave band gaps are obtained. The imperfect interface between the scatterer and the host, namely, the displacement or traction vector are not continuous, are considered. These imperfect interfaces considered include the spring interface, the mass interface, spring-mass interface, and the slide interface. The influence of the imperfect interface upon the wave band gaps is discussed based on the numerical results. Some interesting phenomena are observed and physical explanations are given.