The paper considers the problem of an infinite, homogeneous, isotropic viscoelastic
plane containing multiple circular holes. Constant or time-dependent loading is
applied at infinity or on the boundaries of the holes. The sizes and locations of the
holes are arbitrary provided they do not overlap. The solution of the problem is
based on the use of the correspondence principle, and the governing equation in the
Laplace domain is a complex hypersingular boundary integral equation written in
terms of the unknown transformed displacements at the boundaries of the holes. The
main feature of this equation is that the material parameters are only involved as
multipliers for the terms other than the integrals of transformed displacements. The
unknown transformed displacements are approximated by truncated complex Fourier
series with coefficients dependent on the transform parameter. A system of linear
algebraic equations is formulated using Taylor series expansion for determining
these coefficients. The viscoelastic stresses and displacements are calculated
through the viscoelastic analogs of Kolosov–Muskhelishvili potentials, and
an inverse Laplace transform is used to provide the time domain solution.
All the operations (space integration, Laplace transform and its inversion)
are performed analytically. The method described in the paper enables the
consideration of a variety of viscoelastic models. For the sake of illustration,
examples are given for the cases where the viscoelastic solid responds as (i) a
Boltzmann model in shear and elastically in dilatation, (ii) a Boltzmann
model in both shear and dilatation, and (iii) a Burgers model in shear and
elastically in dilatation. The accuracy and efficiency of the approach are
demonstrated by comparing selected results with the solutions obtained by the
finite element method (ANSYS) and the time stepping boundary element
approach.
Keywords
viscoelasticity, correspondence principle, boundary
integral method, Laplace transform