3.1.10.77. SSPbrickUP Element

This command constructs a stabilized single-point brick element with u-p formulation for analysis of fluid-saturated porous media. Use with -ndm 3 -ndf 4.

element SSPbrickUP $eleTag $N1 $N2 $N3 $N4 $N5 $N6 $N7 $N8 $matTag $fBulk $fDen $k1 $k2 $k3 $e $alpha <$b1 $b2 $b3> <-lumped>

Argument	Type	Description
$eleTag	integer	unique element tag
$N1 … $N8	integer	eight node tags in standard brick order
$matTag	integer	tag of a previously defined ND material
$fBulk	float	fluid bulk modulus
$fDen	float	fluid mass density
$k1 $k2 $k3	float	permeability in local x; y; and z directions
$e	float	void ratio
$alpha	float	\(1 - K_s/K_f\) parameter
$b1 $b2 $b3	float	optional body-force components (default 0.0)
-lumped	string	optional flag to use lumped mass matrix

Note

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

Example

1. Tcl Code

element SSPbrickUP 1 1 2 3 4 5 6 7 8 1 2.2e6 1000.0 1.0e-5 1.0e-5 1.0e-5 0.5 1.0

2. Python Code

element('SSPbrickUP', 1, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2.2e6, 1000.0, 1.0e-5, 1.0e-5, 1.0e-5, 0.5, 1.0)

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