дисперсионное уравнение

Wave Propagation in Fibre-Reinforced Cylinders

Non-stationary wave propagation in cylindrical composite shell is considered. The shell consists of isotropic matrix reinforced by two families of symmetrically wound spiral fibres. These families have the same mechanical properties and the cylinder is considered to be incompressible. Solutions of coupled equations of motion are represented in the form of Frobenius power series. Approximate dispersion relation derived is analyzed numerically for different shell thicknesses and fibre winding angles.

Development of Asymptotic Methods for the Analysis of Dispersion Relations for a Viscoelastic Solid Cylinder

Propagation of time-harmonic waves in a viscoelastic solid cylinder is considered. Vibrations of the cylinder are described by three-dimensional viscoelasticity equations in  cylindrical coordinates. The stress-free surface boundary conditions are imposed. Viscoelastic properties are described by integral operators with a fractional-exponential kernel. For the case of a rational singularity parameter the method of asymptotic analysis of dispersion relations is proposed, which is based on the generalized power series expansion.