CoupledZeroLength
This command is used to construct a CoupledZeroLength element object, which is defined by two nodes at the same location. The nodes are connected a single UniaxialMaterial element to represent the force-deformation relationship for the element in a 2d plane. Unlike a ZeroLength element which can only provide a rectangular force interaction surface in a 2d plane, this element provides a circular force interaction surface.
element CoupledZeroLength $eleTag $iNode $jNode $dirn1
$dirn2 $matTag <$rFlag>
eleTag
|
unique element object tag |
|
end nodes |
matTag
|
tags associated with previously-defined UniaxialMaterial |
|
the two directions, 1 through ndof. |
rFlag
|
optional, default = 0 |
rFlag = 0 NO RAYLEIGH DAMPING (default) |
|
rFlag = 1 include rayleigh damping |
NOTE:
The valid queries to a zero-length element when creating an ElementRecorder object are ‘force,’ and ‘material matArg1 matArg2 …’
Examples
element CoupledZeroLength 1 2 4 5 6 7; # truss tag 1 between nodes 2 and 4 acting in directions 5 and 6 with material 7.
Theory
if change in element end displacements for 2 dof of interest are d1 and d2:
the deformation (strain in uniaxial material) of the material is set to be:
<math>= sqrt( ^2 + ^2)</math>
and if resulting force (stress from uniaxial material) is Sigma then the force computed for the two directions 1 and 2 are:
<math> F_1 = () / </math> <math> F_2 = () / </math>
NOTE: in case where \(\epsilon = 0.0\), the forces are computed using \(\Sigma\) and the last committed set of displacements that were not zero.
Code Developed by: fmk