3.1.10.74. NineFourNodeQuadUP Element

This command constructs a nine-node quadrilateral element (nine-four node) for coupled u-p plane-strain analysis. Corner nodes carry pore pressure; midside nodes carry solid displacement only. Use with -ndm 2. The registered command name is 9_4_QuadUP.

element 9_4_QuadUP $eleTag $N1 $N2 $N3 $N4 $N5 $N6 $N7 $N8 $N9 $thick $matTag $bulk $fmass $permX $permY <$b1 $b2>

Argument	Type	Description
$eleTag	integer	unique element tag
$N1 $N2 $N3 $N4 $N5 $N6 $N7 $N8 $N9	integer	nine node tags
$thick	float	element thickness
$matTag	integer	tag of a previously defined ND material
$bulk	float	combined undrained bulk modulus
$fmass	float	fluid mass density
$permX $permY	float	permeability in x and y directions
$b1 $b2	float	optional body-force components (default 0.0)

Note

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

Example

1. Tcl Code

element 9_4_QuadUP 1 1 2 3 4 5 6 7 8 9 1.0 1 2.2e6 1000.0 1.0e-5 1.0e-5

2. Python Code

element('9_4_QuadUP', 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1.0, 1, 2.2e6, 1000.0, 1.0e-5, 1.0e-5)

Code developed by: Zhaohui Yang, UC San Diego