Manipulation of the guided wave propagation in multilayered phononic plates by introducing interface delaminations

Abstract

In this paper, the manipulation of the guided elastic waves in periodically multilayered elastic plates (PMEPs) by introducing interfacial delaminations is explored. A periodic array of interfacial delaminations (PAIDs) distributed along the direction of wave propagation is considered. The spectral element method (SEM) is adopted and applied to accurately and efficiently calculate the transmission spectra and the band structures of the symmetric and antisymmetric guided elastic waves. The central and side periodic interfacial delaminations are considered separately in this paper. Through the comparison of the band structures for the perfect PMEP and the PMEP with PAIDs, we find that not only the total frequency ranges of the band-gaps are increased significantly, but also all of the band-gaps are moved to the relatively low-frequency ranges when PAIDs exist in a PMEP. Extra band-gaps will be generated, especially some of them are in the low-frequency ranges. In addition, the presence of PAIDs in a PMEP can widen the frequency ranges where the guided waves can only propagate with a single wave mode, i.e. the symmetric wave mode or the antisymmetric wave mode. Thus, the capacity of a PMEP to block or filter the guided waves can be strengthened significantly by just intentionally introducing the interfacial delaminations or cracks, which may provide a new way for the design of novel phononic crystals.