Numerical study of Lamb waves band structure in one-dimensional phononic crystal slabs with the anti-symmetric boundary structure

Abstract

This paper theoretically and numerically investigates the propagation of Lamb waves in a one-dimensional phononic crystal slab bordered with anti-symmetric boundary layers. The results show that the band structure of the anti-symmetric boundary phononic crystal is significantly different from those presented in the papers available. The eigenmodes displacement fields reveal that there is an essential distinction in the formation of the band gap between the anti-symmetric and the symmetric boundary model. On the other hand, the thickness of the boundary layers can remarkably change the width and the location of the band gaps. Furthermore, the variation of the phononic crystal band gaps and the band pinning elimination show the band gaps are sensitive to the degree of stagger of the boundary layers, and different band gap has a different response to the profile of the boundary. In other words, the topological distribution of the boundary layer has an influence on the band structures.