3.1.10.72. bbarQuadUP Element

This command constructs a four-node plane-strain quadrilateral element with the B-bar method to mitigate volumetric locking in coupled u-p analysis. Use with -ndm 2 -ndf 3.

element bbarQuadUP $eleTag $iNode $jNode $kNode $lNode $thick $matTag $bulk $fmass $hPerm $vPerm <$b1 $b2 $t>

Argument	Type	Description
$eleTag	integer	unique element tag
$iNode $jNode $kNode $lNode	integer	four nodes in counter-clockwise order
$thick	float	element thickness
$matTag	integer	tag of a previously defined ND material
$bulk	float	combined undrained bulk modulus
$fmass	float	fluid mass density
$hPerm $vPerm	float	permeability in horizontal and vertical directions
$b1 $b2	float	optional body-force components (default 0.0)
$t	float	optional uniform normal traction (default 0.0)

Note

For the standard formulation without B-bar see FourNodeQuadUP Element.

Example

1. Tcl Code

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

2. Python Code

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

Code developed by: Zhaohui Yang, UC San Diego