
of a spherical inclusion has been studied. An exact
solution to the problem of joint (coupled) seismic
vibrations of an underground pipeline and an
infinite elastic medium is given in the article [4].
Based on the established theorem on the separation
of boundary conditions for wave potentials on the
surface of a cylinder, a method is proposed that
significantly simplifies the solution of the external
problem for the medium. In [5], an exact analytical
solution to the problem of the dynamic expansion of
a spherical cavity in an elastic medium (soil) with
an arbitrary constant speed was obtained. The
solution found makes it possible to judge the impact
(or control the impact) of underground explosions
on objects in the “far” zone, at distances
significantly exceeding the size of the cavity. Article
[6] presents a unified mathematical approach to
describing the dynamic stress-strain state of
mechanical structures made of heterogeneous
materials with a double connected system of pore
channels filled with fluid. New dynamic equations
have been obtained that describe the vibrations of
poroelastic systems based on the developed model
of a continuous medium with additional degrees of
freedom in the form of different pressures of the
components that make up the liquid phase of the
material. In [7], the propagation of non-stationary
longitudinal waves from a spherical cavity
supported by a thin spherical shell in an elastic-
porous space saturated with liquid was studied. An
analytical solution to the problem in the image space
of the Laplace transform is obtained. Numerical
results are presented in the form of graphs. The
article [8] considered the problem of non-stationary
transverse oscillations of an elastic half-space with a
rigid ball. To solve the problem, the Laplace integral
transform and the method of incomplete separation
of variables were used. Formulas for the
components of the displacement vector and stress
tensor are obtained. The paper [9] studies the
interaction of spherical elastic SH waves of
harmonic type with a spherical layer when the
source is placed outside the layer. The exact
solution to this scattering problem is studied in
detail after establishing the generalized Debye
expansion. The problem of the diffraction of plane
waves by a system of two concentric spherical shells
surrounded by acoustic media was studied in the
article [10]. In this case, the solution is represented
in the form of a superposition of elementary waves.
The study [11] considered the problem of the
propagation of shear disturbances from a spherical
cavity in an infinite elastic medium. In this case, the
Fourier transform in time was used. Expressions are
obtained for the displacement and stress over time
caused by an axially symmetric shear stress applied
to the inner surface of a spherical cavity in an
infinite isotropic medium. In [12], the problems of
scattering and diffraction of a cylindrical transverse
shear wave in a viscoelastic isotropic medium by a
spherical inhomogeneity are solved analytically.
The waves are generated by harmonic longitudinal
vibrations of the cylinder walls. The spherical
inclusion is located in the radial center of the
cylinder and differs from the cylindrical material
only in its complex shear modulus. Numerical
examples are given to show the effect of changes in
inclusion rigidity on displacement fields. The paper
[13] addresses the problem of transient
elastodynamics analysis of a thick-walled, fluid-
filled spherical shell embedded in an elastic medium
with an analytical approach. Various constitutive
relations for the elastic medium, shell material, and
fill fluid are considered, as well as various
excitation sources (including S/P wave or
plane/spherical wave incident at different locations).
The statements and solutions of parabolic problems
modeling the physical phenomena in soils in the
case of discontinuous velocity on the boundaries at
the initial time are given in [14]. The notion of
generalized vorticity diffusion is introduced and the
cases of self-similarity existence are classified. In
the case of a physically linear medium, new self-
similar solutions are obtained which describe the
process of unsteady axially symmetric shear in
spherical coordinates. A semi-infinite circular
cylindrical cavity filled with an ideal compressible
liquid that contains a spherical body located near its
face is considered in [15]. A plain acoustic wave
propagates along the axis of the cavity. The problem
of determining of hydrodynamic characteristics of
the system depending on the frequency of the plane
wave and geometrical parameters is solved. The
developed method can detect the anomalous features
of the diffraction of a plane wave due to the
influence of the face wall. This study [16] considers
the propagation of harmonic plane waves in a
double-porosity solid saturated by a viscous fluid.
Two different porosities are supported with different
permeabilities to facilitate the wave-induced fluid
flow in this composite material. Relevant equations
of motion are solved to explain the propagation of
three longitudinal waves and one transverse wave in
the double-porosity dual-permeability medium. A
numerical example is considered to illustrate
dispersion in velocity and attenuation of the four
waves. The effect of wave-induced fluid flow is
analysed with changes in wave-inhomogeneity,
pore-fluid viscosity, and double-porosity structure.
In paper [17] slow motion of a porous spherical
WSEAS TRANSACTIONS on APPLIED and THEORETICAL MECHANICS
DOI: 10.37394/232011.2024.19.15