zeroLengthND Element

element('zeroLengthND', eleTag, *eleNodes, matTag, <uniTag>, <'-orient', *vecx, vecyp>)

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

eleTag (int) unique element object tag
eleNodes (list (int)) a list of two element nodes
matTag (int) tag associated with previously-defined ndMaterial object
uniTag (int) tag associated with previously-defined UniaxialMaterial object which may be used to represent uncoupled behavior orthogonal to the plane of the NDmaterial response. SEE NOTES 2 and 3.
vecx (list (float)) a list of vector components in global coordinates defining local x-axis (optional)
vecyp (list (float)) a list of vector components in global coordinates defining vector yp which lies in the local x-y plane for the element. (optional)


  1. The zeroLengthND element only represents translational response between its nodes
  2. If the NDMaterial object is of order two, the response lies in the element local x-y plane and the UniaxialMaterial object may be used to represent the uncoupled behavior orthogonal to this plane, i.e. along the local z-axis.
  3. If the NDMaterial object is of order three, the response is along each of the element local exes.
  4. 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.
  5. The valid queries to a zero-length element when creating an ElementRecorder object are ‘force’, ‘deformation’, and ‘material matArg1 matArg2 …’

See also