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The propagation of Rayleigh waves along solid surfaces has attracted great attention due to its ubiquity in seismic waves, non-destructive evaluation, acoustic surface wave devices, and so on. Moreover, Rayleigh waves in periodic structures and their related band gaps caused by Bragg resonances have also been investigated. In this paper, we theoretically and experimentally demonstrate the propagation mechanism of Rayleigh waves along the side wall of a periodically corrugated aluminum plate. As expected, the band gap structures are observed in the spectrum of Rayleigh waves. However, not all the band gaps are caused by the Bragg resonances. The additional band gaps created by the interference of different transverse modes are observed. Different from the well-known Bragg resonance, the different mode interference, producing stronger energy attenuation and wider band gap, is called non-Bragg resonances. The two resonances can be manipulated by varying the phase shift of two sidewall corrugations, achieving an effective prohibition of Rayleigh wave propagation. These findings on Rayleigh wave propagation in periodic structures provide a comprehensive understanding of wave-structure interactions, which can be used to regulate elastic waves in various applications, such as multifunctional elastic wave separators, filters, and modulators.

A mono-channel waveguide with alternate hollow pillars of different radius to passively select and reject particular frequencies for filtering applications are numerically simulated based on the Finite Element Method (FEM). The waves are guided while the frequencies can be filtered according to pillar inner radius as its waveguiding mechanism. The computations of dispersion relation, transmission coefficient and stress displacement profile of the waveguides were carried out to understand the propagation behaviour of elastic waves on the waveguide structure. The proposed model shows a complete bandgap around 700 kHz, while its respective blocking phenomenon is demonstrated using square-ring shapes. The introduction of defect lines in linear and L-Shaped form enables a tailorable frequency shift within the bandgap region with optimized inner radius of hollow pillar. The proposed model eliminates the need for a multi-channel filtering system with conventional several separated lines thus reduces the dimension of filtering device.

• Elastic surface waves are excited in an aluminum plate with sidewall corrugations. • The different transverse mode resonances of surface transverse waves are predicted. • The band gaps were manipulated by the relative phase between corrugated surfaces. • The non-Bragg band gaps appear in the high frequency range for asymmetric structures. • The measured dispersion curves confirm the mechanism of phase dependent manipulation. The propagation of Rayleigh waves along solid surfaces has attracted great attention due to its ubiquity in seismic waves, non-destructive evaluation, acoustic surface wave devices, and so on. Moreover, Rayleigh waves in periodic structures and their related band gaps caused by Bragg resonances have also been investigated. In this paper, we theoretically and experimentally demonstrate the propagation mechanism of Rayleigh waves along the side wall of a periodically corrugated aluminum plate. As expected, the band gap structures are observed in the spectrum of Rayleigh waves. However, not all the band gaps are caused by the Bragg resonances. The additional band gaps created by the interference of different transverse modes are observed. Different from the well-known Bragg resonance, the different mode interference, producing stronger energy attenuation and wider band gap, is called non-Bragg resonances. The two resonances can be manipulated by varying the phase shift of two sidewall corrugations, achieving an effective prohibition of Rayleigh wave propagation. These findings on Rayleigh wave propagation in periodic structures provide a comprehensive understanding of wave-structure interactions, which can be used to regulate elastic waves in various applications, such as multifunctional elastic wave separators, filters, and modulators. [ABSTRACT FROM AUTHOR]