NUMERICAL MANIFOLD ELEMENT FOR DYNAMIC ANALYSIS OF SATURATED POROUS MEDIA

A three nodal plane manifold element is developed based on the technique of cover function of numerical manifold method(NMM)for dynamic analysis of saturated porous media.The advantages of the manifold element developed are that it satisfies the so-called Babuska-Brezzi stability criterion and Zienkiewicz-Taylor patch test.The interpolation of displacement and pressure can be determined independently.All nodes of the manifold element have uniform degrees of freedom.The standard Galerkin method and Newmark scheme are used in the spatial and temporal discretization of the governing equations.Compared with the widely used traditional finite element method(FEM),the manifold element method(MEM)presents good stability for the coupling problems,particularly in the nearly incompressible pore fluid and undrained conditions.