Wave propagation analysis of two-phase saturated porous media using coupled finite-infinite element method

A fully coupled two-dimensional infinite element for frequency domain analy sis of wave propagation problems in unbounded saturated porous media is pre sented. The decay function of the element is derived based on the analytica l solution of Blot (Theory of propagation of elastic waves in fluid-saturat ed porous solid. 1. Low-frequency range. Journal of the Acoustical Society of America 1956;28(2):168-78) formulation for a one-dimensional configurati on. After a detailed description of the element formulation, the effectiven ess and the accuracy of the present infinite element in simulating unbounde d domains are demonstrated through two numerical examples. Extremely good a greements are obtained between the results from a very large mesh and those from the coupled finite-infinite element method. It is shown that the accu racy of the solutions deteriorate significantly when the infinite elements are removed and fixed to free displacement boundary conditions are introduc ed at the truncated boundaries. (C) 1999 Elsevier Science Ltd. All rights r eserved.