3.1.10.19. Beam With Hinges Element

This command constructs a force-based beam-column element with plastic hinges at the ends using modified Gauss-Radau integration. The command name in OpenSees is beamWithHinges. The element interior is elastic; nonlinear behavior is concentrated in user-defined hinge sections at ends I and J.

For 2D (ndm=2, ndf=3):

element beamWithHinges $eleTag $iNode $jNode $secTagI $LpI $secTagJ $LpJ $E $A $Iz $transfTag <-mass $massDens> <-iter $maxIters $tol> <-subdivide $numSub $subFac>

For 3D (ndm=3, ndf=6):

element beamWithHinges $eleTag $iNode $jNode $secTagI $LpI $secTagJ $LpJ $E $A $Iz $Iy $G $J $transfTag <-mass $massDens> <-iter $maxIters $tol> <-subdivide $numSub $subFac>

Argument

Type

Description

$eleTag

integer

unique element tag

$iNode $jNode

integer

end node tags

$secTagI $secTagJ

integer

section tags at ends I and J

$LpI $LpJ

float

plastic hinge lengths at ends I and J

$E $A $Iz

float

elastic properties of the interior (2D)

$Iy $G $J

float

additional elastic properties of the interior (3D)

$transfTag

integer

geometric transformation tag

$massDens

float

element mass per unit length (optional; default 0.0)

$maxIters

integer

maximum iterations for element compatibility (optional)

$tol

float

compatibility tolerance used with -iter (optional)

$numSub

integer

number of subdivisions used with -subdivide (optional)

$subFac

float

subdivision factor used with -subdivide (optional)

Note

  1. This legacy format constrains the element interior to remain linear-elastic. For models where plasticity may spread beyond hinge regions, use Force-Based Beam Column Element with HingeRadau (or related) plastic-hinge integration instead.

  2. Hinge integration uses two-point Gauss-Radau over lengths 4*LpI and 4*LpJ at the element ends (six integration points total).

  3. Valid Element Recorder queries are the same as for Force-Based Beam Column Element.

Example

  1. Tcl Code

element beamWithHinges 1 1 2 3 12.0 4 12.0 29000.0 20.0 800.0 1

  1. Python Code

element('beamWithHinges', 1, 1, 2, 3, 12.0, 4, 12.0, 29000.0, 20.0, 800.0, 1)

Code developed by: Michael H. Scott