Displacement-Based Beam-Column Element

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This command is used to construct a displacement beam element object, which is based on the displacement formulation, and considers the spread of plasticity along the element.

element dispBeamColumn $eleTag $iNode $jNode $numIntgrPts $secTag $transfTag <-mass $massDens> <-cMass> <-integration $intType>

To change the sections along the element length, the following form of command may be used:

element dispBeamColumn $eleTag $iNode $jNode $numIntgrPts -sections $secTag1 $secTag2 ... $transfTag <-mass $massDens> <-cMass> <-integration $intType>

$eleTag unique element object tag
$iNode $jNode end nodes
$numIntgrPts number of integration points along the element.
$secTag identifier for previously-defined section object
$secTag1 $secTag2 ... $numIntgrPts identifiers of previously-defined section object
$transfTag identifier for previously-defined coordinate-transformation (CrdTransf) object
$massDens element mass density (per unit length), from which a lumped-mass matrix is formed (optional, default = 0.0)
-cMass to form consistent mass matrix (optional, default = lumped mass matrix)
$intType numerical integration type, options are Lobotto, Legendre, Radau, NewtonCotes, Trapezoidal (optional, default = Legendre)


  • The default integration along the element is based on Gauss-Legendre quadrature rule.
  • The default element is prismatic, i.e. the beam is represented by the section model identified by $secTag at each integration point.
  • The valid queries to a displacement-based beam-column element when creating an ElementRecorder object are 'force,' and 'section $secNum secArg1 secArg2...' Where $secNum refers to the integration point whose data is to be output valid entries being 1 through $numIntgrPts.


element dispBeamColumn 1 2 4 5 8 9; # displacement-based beam column element added with tag 1 between nodes 2 and 4 that has 5 integration points, each using section 8, and the element uses geometric transformation 9


Code Developed by: Michael H. Scott, Oregon State University