Theory of Creeping Waves in Acoustics and Their Experimental Demonstration

Abstract

The theory of creeping waves is developed by applying the Sommerfeld-Watson transformation on the normal-mode solution for acoustic scattering from an infinite elastic cylinder. Two types of radiating, circumferential waves emerge: (1) highly attenuated ‘‘Franz-type” waves with subsonic speeds, and (2) supersonic ‘‘Rayleigh-type” waves which arc only slightly attenuated. The experimental study of these waves for an aluminium cylinder is accomplished by two in­dependent methods: (f) time measurements of sequential pulses, and (2) direct visualization by Schlieren techniques. Measured velocities, attenuations, critical angles, and scattering cross sections are compared with theoretical calculations.

Quantitative Ultrasound Spectroscopy for Screening Cylindrical Lithium‐Ion Batteries for Second‐Life Applications

“…While our preliminary analysis suggests that the quantitative parameters extracted here may be robust to these expansion/contraction changes within our current analysis window, future experiments involving coupled ultrasound measurements and detailed cell thickness assessments could provide a more comprehensive understanding, particularly in the context of potential aging effects. Furthermore, prior studies have examined ultrasonic methods in cylindrical structures like pipelines and fluid‐filled shells, demonstrating the effectiveness of these techniques in gathering internal information from such structures [73,74] …”

“…Furthermore, prior studies have examined ultrasonic methods in cylindrical structures like pipelines and fluid-filled shells, demonstrating the effectiveness of these techniques in gathering internal information from such structures. [73,74] Ultrasound propagation in intricate structures, like the "jelly roll" form of cylindrical batteries, presents significant complexities. The simulation employed in our study qualitatively elucidates the ultrasonic wave propagation mechanisms in cylindrical batteries under specific experimental conditions.…”

Subsurface defect characterization using laser ultrasonic technique for metal additive manufacturing

“…(i) The wave front C for the Rayleigh-type creeping wave is always in front of the wave front B for Franz-type wave in Figure 3.6, due to the different angles of incidence at the defect cross-section. Franz-type creeping wave generates at the tangential incidence, whereas the Rayleigh-type wave generates non-tangentially at a critical angle that is dependent on its wave dispersion relation [50]. This means that the latter can make more circumnavigations around the defect than the former.…”