The Propagation and Radiation of Elastic Waves in Isotropic and Anisotropic Bodies

The mathematical models of elastic wave propagation in an elastic bar and an elastic shell are very
close to each other. The contact boundary value problem formulated for a shell differs from the one
formulated for a bar in that it contains an additional boundary surface, which leads to an additional
number of unknown coefficients determined by the additional boundary conditions. By contrast, at
high frequencies, the wave processes in a shell differ little from those in a layer; therefore, a
simultaneous study of these structures is justified. We begin with the more simple of the two
structures: namely, the bar.