3.1.10.6. zeroLengthContactNTS2D Element

This command is used to construct a node-to-segment (NTS) frictional contact element for 2D analysis. The relation follows the Mohr-Coulomb frictional law: \(T = N \times \tan(\phi)\), where \(T\) is tangential force, \(N\) is normal force, and \(\phi\) is friction angle.

element zeroLengthContactNTS2D $eleTag -sNdNum $sNdNum -mNdNum $mNdNum -Nodes $nodeTags $kn $kt $phi

Argument

Type

Description

$eleTag

integer

unique element object tag

$sNdNum

integer

number of slave nodes

$mNdNum

integer

number of master nodes

$nodeTags

list integer

slave and master node tags (counterclockwise order)

$kn

float

penalty in normal direction

$kt

float

penalty in tangential direction

$phi

float

friction angle in degrees

Note

  1. Slave and master nodes must have 2 DOF and be entered in counterclockwise order.

  2. The tangent from the contact element is non-symmetric; use a non-symmetric system solver if convergence is difficult.

  3. The contact normal is computed automatically (no predefined normal vector required).

  4. The element supports large deformations.

See also

Notes (OpenSees wiki)

Example

From the OpenSees wiki: element with tag 1, 6 slave and 6 master nodes, node tags as listed, kn = kt = 1e8, friction angle 16°.

  1. Tcl Code

element zeroLengthContactNTS2D 1 -sNdNum 6 -mNdNum 6 -Nodes 5 10 12 3 9 11 1 4 2 8 7 6 1e8 1e8 16

  1. Python Code

ops.element('zeroLengthContactNTS2D', 1, '-sNdNum', 6, '-mNdNum', 6, '-Nodes', 5, 10, 12, 3, 9, 11, 1, 4, 2, 8, 7, 6, 1e8, 1e8, 16)

References: Wriggers, P., Computational Contact Mechanics, John Wiley & Sons, 2002.

Code developed by: Roozbeh G. Mikola, UC Berkeley and N. Sitar, UC Berkeley