3.1.10.71. BrickUP Element

This command constructs an eight-node hexahedral brick element for coupled solid-fluid (u-p) analysis of saturated porous media. Each node has three solid displacement DOFs and one pore-pressure DOF. Use with -ndm 3 -ndf 4.

element brickUP $eleTag $N1 $N2 $N3 $N4 $N5 $N6 $N7 $N8 $matTag $bulk $fmass $permX $permY $permZ <$bX $bY $bZ>

Argument	Type	Description
$eleTag	integer	unique element tag
$N1 $N2 $N3 $N4 $N5 $N6 $N7 $N8	integer	eight node tags in standard brick order
$matTag	integer	tag of a previously defined ND material
$bulk	float	combined undrained bulk modulus relating pore pressure and volumetric strain
$fmass	float	fluid mass density
$permX $permY $permZ	float	permeability in x; y; and z directions
$bX $bY $bZ	float	optional body-force components (default 0.0)

Note

1. Record pore pressure at nodes with a Node Recorder on DOF 4.

2. Valid Element Recorder queries include force and material $matNum ....

Example

1. Tcl Code

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

2. Python Code

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

Code developed by: Zhaohui Yang, UC San Diego