Guided Wave Propagation in Complex Curved Waveguides I: Method   Introduction and Verification
  A phenomenological method is developed to consider elastic guided wave propagation in complex curved waveguides. The theory on guided wave propagation in hollow circular cylinders is used in order to verify the method. The results are compared with solutions obtained by the Helmholtz decomposition method. The method given here is used to derive new analytical relations for torsional and longitudinal phase velocity dispersion curves. In addition, a new excitation method is proposed and examined for flexural modes. Some conceptual results and applications of the method are discussed. 
E. Khajeh, L. Breon, J. L. Rose
physics.class-ph