Guided waves' dispersion curves in anisotropic viscoelastic single- and multi-layered media

Full 3D dispersion curve solutions for guided waves in generally anisotropic media

“…A comprehensive description of the SCM is in [12], [14] and, with particular relevance to the present case, in [15]. The main idea behind the SCM is to convert the partial differential equations of the acoustic field into a generalized matrix eigenvalue problem whose eigenvalues are computed thus yielding the full spectrum.…”

“…When material damping is included, that is, when modelling viscoelastic media, the viscoelastic stress tensor field takes the following more complex form assuming the Kelvin-Voigt frequency dependent model (see [15] for details) to account for material damping:…”

“…In section 2 a very brief description of the SCM, and its implementation is given, this is kept to a minimum to avoid repetition and the reader is referred to [12], [14], [15] and references therein for all the details about the SCM scheme and an extensive discussion of its principal features when used to solve acoustic guided wave problems. Some modifications are required here and these are outlined.…”

“…More recently, one of these variants known as Spectral Collocation Method (SCM) has been successfully used to model guided waves in elastic and viscoelastic generally anisotropic media, [14] and [15] respectively.…”

“…The SCM used here was first presented in a previous work by Hernando et. al [15], though there, attention was restricted solely to lowly attenuated modes. The present work goes one step further and, by carefully sorting the eigenvalues provided by the SCM, completes the picture giving the remaining branches of the dispersion loci for the most general anisotropic triclinic class.…”