3.1.10.75. TwentyEightNodeBrickUP Element

This command constructs a 20-node hexahedral element for coupled u-p analysis. Eight corner nodes have pore-pressure DOFs; twelve midside nodes carry solid displacement only. Use with -ndm 3. The registered command name is 20_8_BrickUP.

element 20_8_BrickUP $eleTag $N1 $N2 $N3 $N4 $N5 $N6 $N7 $N8 $N9 $N10 $N11 $N12 $N13 $N14 $N15 $N16 $N17 $N18 $N19 $N20 $matTag $bulk $fmass $permX $permY $permZ <$bX $bY $bZ>

Argument	Type	Description
$eleTag	integer	unique element tag
$N1 … $N20	integer	twenty node tags in standard 20-node brick order
$matTag	integer	tag of a previously defined ND material
$bulk	float	combined undrained bulk modulus
$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

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

Example

1. Tcl Code

element 20_8_BrickUP 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 2.2e6 1000.0 1.0e-5 1.0e-5 1.0e-5

2. Python Code

element('20_8_BrickUP', 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
        1, 2.2e6, 1000.0, 1.0e-5, 1.0e-5, 1.0e-5)

Code developed by: Zhaohui Yang, UC San Diego