Numerical analysis of poroviscoelastic prismatic solids and halfspaces dynamics via boundary element method

Dynamic behavior of poroelastic and poroviscoelastic solids is considered. Poroviscoelastic formulation is based on Biot’s model of fully saturated poroelastic media. The elastic-viscoelastic correspondence principle is applied to describe viscoelastic properties of elastic skeleton. Viscoelastic constitutive equations are introduced. Classical viscoelastic models are used, such as Kelvin-Voigt, Standard linear solid and model with weakly singular kernel of Abel type. Differential equation system of full Biot’s model in Laplace transform and formulas for elastic modules are given. Original problem’s solution is built in Laplace transform and numerical inversion is used to obtain the solution in time domain. Direct boundary integral equation (BIE) system is introduced. Regularized BIE system is considered. Mixed boundary element discretization is introduced to obtain discrete analogues. Gaussian quadrature and hierarchic integrating algorithm are used for integration over the boundary elements. Numerical inversion of Laplace transform is done by means of modified Durbin’s algorithm with a variable integrating step. The described numerical scheme is verified by a comparison with analytical solution in a one-dimensional case. Isotropic poroviscoelastic solids and halfspaces are considered. Results of numerical experiments are presented. Problems of axial force acting on the end of prismatic solid and vertical force acting on a halfspace are solved. Viscous parameter influence on dynamic responses of displacements and pore pressure are studied. Surface waves on poroviscoelastic halfspace are modelled with the help of boundary element method.