An iterative stabilized fractional step algorithm for finite element analysis in saturated soil dynamics Original Research Article

The discretization of the u–p model for saturated porous media results in the semi-discrete system of mixed type in displacements and pressures. The Babuska–Brezzi condition or the simpler patch test proposed by Zienkiewicz and Taylor precludes the use of elements with the equal low order of interpolation for u and p, unless special stabilization techniques, such as the fractional step algorithms, are used. The purpose of this paper is to present a modified version of the fractional step algorithm which allows much larger time step sizes than those for the existing ones. The method is based on introducing an iteration algorithm. The numerical experiments demonstrate the effectiveness and improved performance of the proposed modified version of the fractional step algorithm.