Stabilized single-point 4-node quadrilateral element for dynamic analysis of fluid saturated porous media

An accurate and efficient low-order quadrilateral mixed u-p element suitable for dynamic analysis of fluid saturated porous media is presented. The element uses physical hourglass stabilization to facilitate single-point integration for the solid phase, and non-residual stabilization of the fluid phase to circumvent instability in the incompressible-impermeable limit due to the use of equal-order interpolation for the displacement and pressure fields. Element behavior is verified and demonstrated through several numerical examples.