title: Dispersion analysis and measurement of circular cylindrical wedge-like acoustic waveguides.
abstract: This study investigated the propagation of flexural waves along the outer edge of a circular cylindrical wedge, the phase velocities, and the corresponding mode displacements. Thus far, only approximate solutions have been derived because the corresponding boundary-value problems are complex. In this study, dispersion curves were determined using the bi-dimensional finite element method and derived through the separation of variables and the Hamilton principle. Modal displacement calculations clarified that the maximal deformations appeared at the outer edge of the wedge tip. Numerical examples indicated how distinct thin-film materials deposited on the outer surface of the circular cylindrical wedge influenced the dispersion curves. Additionally, dispersion curves were measured using a laser-induced guided wave, a knife-edge measurement scheme, and a two-dimensional fast Fourier transform method. Both the numerical and experimental results correlated closely, thus validating the numerical solution.
authors.affiliation: Department of Electronic Engineering, National United University, 2 Lienda, Nan-Shih Li, Miaoli 36063, Taiwan, ROC. Electronic address: yth@nuu.edu.tw.
authors.forename: Tai-Ho
authors.initials: TH
authors.lastname: Yu
keywords: Bi-dimensional finite element method (bi-d FEM); Circular cylindrical wedge-like acoustic waveguide; Knife-edge technique; Two-dimensional fast Fourier transform (2D-FFT)