3.1.10.76. SSPquadUP Element

This command constructs a stabilized single-point quadrilateral element with u-p formulation for plane-strain analysis of fluid-saturated porous media. Use with -ndm 2 -ndf 3.

element SSPquadUP $eleTag $iNode $jNode $kNode $lNode $matTag $t $fBulk $fDen $k1 $k2 $e $alpha <$b1 $b2> <$Pup $Plow $Pleft $Pright>

Argument	Type	Description
$eleTag	integer	unique element tag
$iNode $jNode $kNode $lNode	integer	four nodes in counter-clockwise order
$matTag	integer	tag of a previously defined ND material
$t	float	element thickness
$fBulk	float	fluid bulk modulus
$fDen	float	fluid mass density
$k1 $k2	float	permeability in local x and y directions
$e	float	void ratio
$alpha	float	\(1 - K_s/K_f\) parameter
$b1 $b2	float	optional body-force components (default 0.0)
$Pup $Plow $Pleft $Pright	float	optional boundary pore pressures on element edges

Note

Valid Element Recorder queries include force, stress, and material $matNum ....

Example

1. Tcl Code

element SSPquadUP 1 1 2 3 4 1 1.0 2.2e6 1000.0 1.0e-5 1.0e-5 0.5 1.0

2. Python Code

element('SSPquadUP', 1, 1, 2, 3, 4, 1, 1.0, 2.2e6, 1000.0, 1.0e-5, 1.0e-5, 0.5, 1.0)

Code developed by: Chris McGann, Pedro Arduino, and Peter Mackenzie-Helnwein, University of Washington