Helical Wave Spectrum of Bending Waves in an Infinite Composite Cylinder with Periodic Rings

Bending waves in an infinite composite cylinder with periodic rings are addressed in terms of helical wave spectra. The presence of periodic rings that results in the well-known wave conversion effect is clearly identified from the contour plot of helical wave spectra. Accordingly, the periodic rings have significant contributions to sound radiation which can be deduced from the curves of radiating components in wave number domain. This work can provide an in-depth understanding of the mechanism of sound radiation from composite cylinders with doubly periodic rings.