ZeroLengthSection Element

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This command is used to construct a zero length element object, which is defined by two nodes at the same location. The nodes are connected by a single section object to represent the force-deformation relationship for the element.

element zeroLengthSection $eleTag $iNode $jNode $secTag <-orient $x1 $x2 $x3 $yp1 $yp2 $yp3> <-doRayleigh $rFlag>

$eleTag unique element object tag
$iNode $jNode end nodes
$secTag tag associated with previously-defined Section object
$x1 $x2 $x3 vector components in global coordinates defining local x-axis (optional)
$yp1 $yp2 $yp3 vector components in global coordinates defining vector yp which lies in the local x-y plane for the element. (optional)
$rFlag optional, default = 1
rFlag = 0 no Rayleigh damping
rFlag = 1 include Rayleigh damping (default)


  1. If the optional orientation vectors are not specified, the local element axes coincide with the global axes. Otherwise the local z-axis is defined by the cross product between the vectors x and yp vectors specified on the command line.
  2. The section force-deformation response represented by section string P acts along the element local x-axis, and the response for code Vy along the local y-axis. The other modes of section response follow from this orientation.
  3. The valid queries to a zero-length element when creating an ElementRecorder object are 'force,' 'deformation,' 'stiff,' and 'section $secArg1 secArg2 ...'.


element zeroLengthSection 1 2 4 6; # truss tag 1 between nodes 2 and 4 usinga type 6 section.

element zeroLengthSection 1 1 2 1 -orient 0 1 0 0 0 -1; # element tag 1 between nodes 1 and 2 defined with section 1. Local direction x, perpendicular to element section, is aligned with the global Y axis and the vector yp is aligned with the negative global Z axis.

Code Developed by: Micheal Scott, Oregon State University.