A finite element-thin layer element coupling method for near-field wave propagation in fluid-saturated porous media based on u-U dynamic formulation

Abstract

A finite element-thin layer element coupling method for the near-field wave propagation analysis in the fluid-saturated porous media (FSPM) is developed based on the Biot u-U dynamic formulation. The case of the wave propagation normal to the boundary of calculating domain is investigated. The wave propagation equations are decoupled by the variables-separating method. The finite element method is adopted for the space discretization and numerical analysis of the finite domain, and the thin layer element method is applied to discretize the infinite domain and construct the consistent artificial boundary condition. This method is validated and then applied to the analysis to the near-field wave propagation problem of FSPM. Parametric sensitivity studies are conducted to analyze the effect of the mechanical parameters, including permeability coefficient, porosity, and Young's modulus of solid skeleton, on the dynamic response of FSPM. The study results indicate the effectiveness and efficiency of the developed method to the near-field wave propagation analysis in FSPM.