title: A remark on the computation of shear-horizontal and torsional modes in elastic waveguides.
abstract: When modeling the propagation of elastic guided waves in plates or cylinders, Finite Element based numerical methods such as the Scaled Boundary Finite Element Method (SBFEM) or the Semi-Analytical Finite Element (SAFE) Method lead to an eigenvalue problem to be solved at each frequency. For the particular case of shear horizontal modes in a homogeneous plate or torsional modes in a homogeneous cylinder, the problem can be drastically simplified. The eigenvalues become simple functions of the frequency, while the eigenvectors are constant. The current contribution discusses how this behavior is represented in the numerical formulation and derives the expressions for the eigenvalues and eigenvectors as well as the dynamic stiffness matrix of infinite elastic waveguides.
authors.affiliation: Federal Institute for Materials Research and Testing, 12200 Berlin, Germany. Electronic address: hauke.gravenkamp@uni-due.de.
authors.forename: Hauke
authors.initials: H
authors.lastname: Gravenkamp
keywords: Guided waves; Scaled Boundary Finite Element Method; Shear-horizontal modes; Torsional modes