ELASTIC WAVE TRANSMISSION THROUGH PERIODIC LAYERS HAVING A DEFECT ARRAY

Abstract

This paper presents an FE-based elastic wave transmission analysis method for a composite layer in which defects are imbedded periodically. Scattering waves originated from the defects are represented by a dynamic load acting on a contour surrounding the defect. This formulation enables to reduce the original problem to the dynamic reaction of the periodic layer without defects. By virtue of Floquet transform, the solution is derived from FE analyses of a unit region of the periodic layer. Numerical results showed that the introduction of a defect array contributes to the enhancement of capability for insulation, while the stop band will be vanished.